From 0355257f8360e06b80ebe5ac25b9378249757e93 Mon Sep 17 00:00:00 2001
From: Neil Deakin <neil@mozilla.com>
Date: Fri, 24 Jan 2020 19:53:55 +0000
Subject: [PATCH] Bug 1505915, move view source components to use
 JSWindowActor. This allows view frame source to work in out of process child
 frames, r=mconley

Differential Revision: https://phabricator.services.mozilla.com/D60253

--HG--
rename : toolkit/components/viewsource/content/viewSource-content.js => toolkit/actors/ViewSourceChild.jsm
rename : toolkit/components/viewsource/content/viewSource-content.js => toolkit/actors/ViewSourcePageChild.jsm
rename : toolkit/components/viewsource/ViewSourceBrowser.jsm => toolkit/actors/ViewSourcePageParent.jsm
extra : moz-landing-system : lando
---
 browser/base/content/nsContextMenu.js         |   5 +-
 .../components/sessionstore/SessionStore.jsm  |   7 -
 ...ionSourceChild.jsm => ViewSourceChild.jsm} | 187 ++++++-
 .../ViewSourcePageChild.jsm}                  | 457 ++++--------------
 toolkit/actors/ViewSourcePageParent.jsm       | 159 ++++++
 toolkit/actors/moz.build                      |   4 +-
 .../viewsource/ViewSourceBrowser.jsm          | 335 -------------
 .../viewsource/content/viewSourceUtils.js     |  78 +--
 toolkit/components/viewsource/jar.mn          |   1 -
 toolkit/components/viewsource/moz.build       |   4 -
 .../viewsource/test/browser/browser.ini       |   1 +
 .../test/browser/browser_gotoline.js          |  10 +-
 .../test/browser/browser_partialsource.js     |  46 ++
 .../viewsource/test/browser/head.js           |  21 +-
 toolkit/modules/ActorManagerParent.jsm        |  36 +-
 15 files changed, 579 insertions(+), 772 deletions(-)
 rename toolkit/actors/{SelectionSourceChild.jsm => ViewSourceChild.jsm} (58%)
 rename toolkit/{components/viewsource/content/viewSource-content.js => actors/ViewSourcePageChild.jsm} (57%)
 create mode 100644 toolkit/actors/ViewSourcePageParent.jsm
 delete mode 100644 toolkit/components/viewsource/ViewSourceBrowser.jsm
 create mode 100644 toolkit/components/viewsource/test/browser/browser_partialsource.js

diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
index 8df171ef2ea9..523a5f35435e 100644
--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -1174,7 +1174,10 @@ class nsContextMenu {
       return viewSourceBrowser;
     };
 
-    top.gViewSourceUtils.viewPartialSourceInBrowser(browser, openSelectionFn);
+    top.gViewSourceUtils.viewPartialSourceInBrowser(
+      this.actor.browsingContext,
+      openSelectionFn
+    );
   }
 
   // Open new "view source" window with the frame's URL.
diff --git a/browser/components/sessionstore/SessionStore.jsm b/browser/components/sessionstore/SessionStore.jsm
index 9e6a82899e08..fd0af29adbf2 100644
--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@@ -208,7 +208,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   TabStateCache: "resource:///modules/sessionstore/TabStateCache.jsm",
   TabStateFlusher: "resource:///modules/sessionstore/TabStateFlusher.jsm",
   Utils: "resource://gre/modules/sessionstore/Utils.jsm",
-  ViewSourceBrowser: "resource://gre/modules/ViewSourceBrowser.jsm",
   setTimeout: "resource://gre/modules/Timer.jsm",
 });
 
@@ -4710,12 +4709,6 @@ var SessionStoreInternal = {
       });
     }
 
-    // If the restored browser wants to show view source content, start up a
-    // view source browser that will load the required frame script.
-    if (uri && ViewSourceBrowser.isViewSource(uri)) {
-      new ViewSourceBrowser(browser);
-    }
-
     browser.messageManager.sendAsyncMessage("SessionStore:restoreTabContent", {
       loadArguments,
       isRemotenessUpdate,
diff --git a/toolkit/actors/SelectionSourceChild.jsm b/toolkit/actors/ViewSourceChild.jsm
similarity index 58%
rename from toolkit/actors/SelectionSourceChild.jsm
rename to toolkit/actors/ViewSourceChild.jsm
index 74cac7676979..c36d79022b1d 100644
--- a/toolkit/actors/SelectionSourceChild.jsm
+++ b/toolkit/actors/ViewSourceChild.jsm
@@ -3,28 +3,183 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-var EXPORTED_SYMBOLS = ["SelectionSourceChild"];
+var EXPORTED_SYMBOLS = ["ViewSourceChild"];
 
-const { ActorChild } = ChromeUtils.import(
-  "resource://gre/modules/ActorChild.jsm"
-);
 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
-class SelectionSourceChild extends ActorChild {
-  receiveMessage(message) {
-    const global = message.target;
+ChromeUtils.defineModuleGetter(
+  this,
+  "ViewSourcePageChild",
+  "resource://gre/actors/ViewSourcePageChild.jsm"
+);
 
-    if (message.name == "ViewSource:GetSelection") {
-      let selectionDetails;
-      try {
-        selectionDetails = this.getSelection(global);
-      } finally {
-        global.sendAsyncMessage(
-          "ViewSource:GetSelectionDone",
-          selectionDetails
+class ViewSourceChild extends JSWindowActorChild {
+  receiveMessage(message) {
+    let data = message.data;
+    switch (message.name) {
+      case "ViewSource:LoadSource":
+        this.viewSource(
+          data.URL,
+          data.outerWindowID,
+          data.lineNumber,
+          data.shouldWrap
         );
+        break;
+      case "ViewSource:LoadSourceWithSelection":
+        this.viewSourceWithSelection(
+          data.URL,
+          data.drawSelection,
+          data.baseURI
+        );
+        break;
+      case "ViewSource:GetSelection":
+        let selectionDetails;
+        try {
+          selectionDetails = this.getSelection(this.document.ownerGlobal);
+        } catch (e) {}
+        return selectionDetails;
+    }
+
+    return undefined;
+  }
+
+  /**
+   * Called when the parent sends a message to view some source code.
+   *
+   * @param URL (required)
+   *        The URL string of the source to be shown.
+   * @param outerWindowID (optional)
+   *        The outerWindowID of the content window that has hosted
+   *        the document, in case we want to retrieve it from the network
+   *        cache.
+   * @param lineNumber (optional)
+   *        The line number to focus as soon as the source has finished
+   *        loading.
+   */
+  viewSource(URL, outerWindowID, lineNumber) {
+    let pageDescriptor, forcedCharSet;
+
+    if (outerWindowID) {
+      let contentWindow = Services.wm.getOuterWindowWithId(outerWindowID);
+      if (contentWindow) {
+        let otherDocShell = contentWindow.docShell;
+
+        try {
+          pageDescriptor = otherDocShell.QueryInterface(Ci.nsIWebPageDescriptor)
+            .currentDescriptor;
+        } catch (e) {
+          // We couldn't get the page descriptor, so we'll probably end up re-retrieving
+          // this document off of the network.
+        }
+
+        let utils = contentWindow.windowUtils;
+        let doc = contentWindow.document;
+        forcedCharSet = utils.docCharsetIsForced ? doc.characterSet : null;
       }
     }
+
+    this.loadSource(URL, pageDescriptor, lineNumber, forcedCharSet);
+  }
+
+  /**
+   * Loads a view source selection showing the given view-source url and
+   * highlight the selection.
+   *
+   * @param uri view-source uri to show
+   * @param drawSelection true to highlight the selection
+   * @param baseURI base URI of the original document
+   */
+  viewSourceWithSelection(uri, drawSelection, baseURI) {
+    // This isn't ideal, but set a global in the view source page actor
+    // that indicates that a selection should be drawn. It will be read
+    // when by the page's pageshow listener. This should work as the
+    // view source page is always loaded in the same process.
+    ViewSourcePageChild.setNeedsDrawSelection(drawSelection);
+
+    // all our content is held by the data:URI and URIs are internally stored as utf-8 (see nsIURI.idl)
+    let loadFlags = Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
+    let webNav = this.docShell.QueryInterface(Ci.nsIWebNavigation);
+    let loadURIOptions = {
+      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
+      loadFlags,
+      baseURI: Services.io.newURI(baseURI),
+    };
+    webNav.loadURI(uri, loadURIOptions);
+  }
+
+  /**
+   * Common utility function used by both the current and deprecated APIs
+   * for loading source.
+   *
+   * @param URL (required)
+   *        The URL string of the source to be shown.
+   * @param pageDescriptor (optional)
+   *        The currentDescriptor off of an nsIWebPageDescriptor, in the
+   *        event that the caller wants to try to load the source out of
+   *        the network cache.
+   * @param lineNumber (optional)
+   *        The line number to focus as soon as the source has finished
+   *        loading.
+   * @param forcedCharSet (optional)
+   *        The document character set to use instead of the default one.
+   */
+  loadSource(URL, pageDescriptor, lineNumber, forcedCharSet) {
+    const viewSrcURL = "view-source:" + URL;
+
+    if (forcedCharSet) {
+      try {
+        this.docShell.charset = forcedCharSet;
+      } catch (e) {
+        /* invalid charset */
+      }
+    }
+
+    ViewSourcePageChild.setInitialLineNumber(lineNumber);
+
+    if (!pageDescriptor) {
+      this.loadSourceFromURL(viewSrcURL);
+      return;
+    }
+
+    try {
+      let pageLoader = this.docShell.QueryInterface(Ci.nsIWebPageDescriptor);
+      pageLoader.loadPage(
+        pageDescriptor,
+        Ci.nsIWebPageDescriptor.DISPLAY_AS_SOURCE
+      );
+    } catch (e) {
+      // We were not able to load the source from the network cache.
+      this.loadSourceFromURL(viewSrcURL);
+      return;
+    }
+
+    let shEntrySource = pageDescriptor.QueryInterface(Ci.nsISHEntry);
+    let shistory = this.docShell.QueryInterface(Ci.nsIWebNavigation)
+      .sessionHistory.legacySHistory;
+    let shEntry = shistory.createEntry();
+    shEntry.URI = Services.io.newURI(viewSrcURL);
+    shEntry.title = viewSrcURL;
+    let systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
+    shEntry.triggeringPrincipal = systemPrincipal;
+    shEntry.setLoadTypeAsHistory();
+    shEntry.cacheKey = shEntrySource.cacheKey;
+    shistory.addEntry(shEntry, true);
+  }
+
+  /**
+   * Load some URL in the browser.
+   *
+   * @param URL
+   *        The URL string to load.
+   */
+  loadSourceFromURL(URL) {
+    let loadFlags = Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
+    let webNav = this.docShell.QueryInterface(Ci.nsIWebNavigation);
+    let loadURIOptions = {
+      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
+      loadFlags,
+    };
+    webNav.loadURI(URL, loadURIOptions);
   }
 
   /**
@@ -213,7 +368,7 @@ class SelectionSourceChild extends ActorChild {
     tmpNode.appendChild(ancestorContainer);
 
     return {
-      uri:
+      URL:
         (isHTML
           ? "view-source:data:text/html;charset=utf-8,"
           : "view-source:data:application/xml;charset=utf-8,") +
diff --git a/toolkit/components/viewsource/content/viewSource-content.js b/toolkit/actors/ViewSourcePageChild.jsm
similarity index 57%
rename from toolkit/components/viewsource/content/viewSource-content.js
rename to toolkit/actors/ViewSourcePageChild.jsm
index 7d4689868220..687b676f4e3a 100644
--- a/toolkit/components/viewsource/content/viewSource-content.js
+++ b/toolkit/actors/ViewSourcePageChild.jsm
@@ -9,11 +9,7 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 
-ChromeUtils.defineModuleGetter(
-  this,
-  "DeferredTask",
-  "resource://gre/modules/DeferredTask.jsm"
-);
+var EXPORTED_SYMBOLS = ["ViewSourcePageChild"];
 
 XPCOMUtils.defineLazyGlobalGetters(this, ["NodeFilter"]);
 
@@ -28,280 +24,105 @@ const BUNDLE_URL = "chrome://global/locale/viewSource.properties";
 const MARK_SELECTION_START = "\uFDD0";
 const MARK_SELECTION_END = "\uFDEF";
 
-var global = this;
+/**
+ * When showing selection source, chrome will construct a page fragment to
+ * show, and then instruct content to draw a selection after load.  This is
+ * set true when there is a pending request to draw selection.
+ */
+let gNeedsDrawSelection = false;
 
 /**
- * ViewSourceContent should be loaded in the <xul:browser> of the
- * view source window, and initialized as soon as it has loaded.
+ * Start at a specific line number.
  */
-var ViewSourceContent = {
-  /**
-   * These are the messages that ViewSourceContent is prepared to listen
-   * for. If you need ViewSourceContent to handle more messages, add them
-   * here.
-   */
-  messages: [
-    "ViewSource:LoadSource",
-    "ViewSource:LoadSourceWithSelection",
-    "ViewSource:GoToLine",
-  ],
+let gInitialLineNumber = -1;
 
-  /**
-   * When showing selection source, chrome will construct a page fragment to
-   * show, and then instruct content to draw a selection after load.  This is
-   * set true when there is a pending request to draw selection.
-   */
-  needsDrawSelection: false,
-
-  get isViewSource() {
-    let uri = content.document.documentURI;
-    return uri.startsWith("view-source:");
+/**
+ * In-page context menu items that are injected after page load.
+ */
+let gContextMenuItems = [
+  {
+    id: "goToLine",
+    accesskey: true,
+    handler(actor) {
+      actor.sendAsyncMessage("ViewSource:PromptAndGoToLine");
+    },
   },
-
-  get isAboutBlank() {
-    let uri = content.document.documentURI;
-    return uri == "about:blank";
+  {
+    id: "wrapLongLines",
+    get checked() {
+      return Services.prefs.getBoolPref("view_source.wrap_long_lines");
+    },
+    handler(actor) {
+      actor.toggleWrapping();
+    },
   },
+  {
+    id: "highlightSyntax",
+    get checked() {
+      return Services.prefs.getBoolPref("view_source.syntax_highlight");
+    },
+    handler(actor) {
+      actor.toggleSyntaxHighlighting();
+    },
+  },
+];
 
-  /**
-   * This should be called as soon as this frame script has loaded.
-   */
-  init() {
-    this.messages.forEach(msgName => {
-      addMessageListener(msgName, this);
+class ViewSourcePageChild extends JSWindowActorChild {
+  constructor() {
+    super();
+
+    XPCOMUtils.defineLazyGetter(this, "bundle", function() {
+      return Services.strings.createBundle(BUNDLE_URL);
     });
+  }
 
-    addEventListener("pagehide", this, true);
-    addEventListener("pageshow", this, true);
-    addEventListener("click", this);
-    addEventListener("unload", this);
-    Services.els.addSystemEventListener(global, "contextmenu", this, false);
-  },
+  static setNeedsDrawSelection(value) {
+    gNeedsDrawSelection = value;
+  }
 
-  /**
-   * This should be called when the frame script is being unloaded,
-   * and the browser is tearing down.
-   */
-  uninit() {
-    this.messages.forEach(msgName => {
-      removeMessageListener(msgName, this);
-    });
+  static setInitialLineNumber(value) {
+    gInitialLineNumber = value;
+  }
 
-    removeEventListener("pagehide", this, true);
-    removeEventListener("pageshow", this, true);
-    removeEventListener("click", this);
-    removeEventListener("unload", this);
-
-    Services.els.removeSystemEventListener(global, "contextmenu", this, false);
-  },
-
-  /**
-   * Anything added to the messages array will get handled here, and should
-   * get dispatched to a specific function for the message name.
-   */
   receiveMessage(msg) {
-    if (!this.isViewSource && !this.isAboutBlank) {
-      return;
+    if (msg.name == "ViewSource:GoToLine") {
+      this.goToLine(msg.data.lineNumber);
     }
-    let data = msg.data;
-    switch (msg.name) {
-      case "ViewSource:LoadSource":
-        this.viewSource(
-          data.URL,
-          data.outerWindowID,
-          data.lineNumber,
-          data.shouldWrap
-        );
-        break;
-      case "ViewSource:LoadSourceWithSelection":
-        this.viewSourceWithSelection(
-          data.URL,
-          data.drawSelection,
-          data.baseURI
-        );
-        break;
-      case "ViewSource:GoToLine":
-        this.goToLine(data.lineNumber);
-        break;
-    }
-  },
+  }
 
   /**
    * Any events should get handled here, and should get dispatched to
    * a specific function for the event type.
    */
   handleEvent(event) {
-    if (!this.isViewSource) {
-      return;
-    }
     switch (event.type) {
-      case "pagehide":
-        this.onPageHide(event);
-        break;
       case "pageshow":
         this.onPageShow(event);
         break;
       case "click":
         this.onClick(event);
         break;
-      case "unload":
-        this.uninit();
-        break;
-      case "contextmenu":
-        this.onContextMenu(event);
-        break;
     }
-  },
-
-  /**
-   * A getter for the view source string bundle.
-   */
-  get bundle() {
-    delete this.bundle;
-    this.bundle = Services.strings.createBundle(BUNDLE_URL);
-    return this.bundle;
-  },
+  }
 
   /**
    * A shortcut to the nsISelectionController for the content.
    */
   get selectionController() {
-    return docShell
+    return this.docShell
       .QueryInterface(Ci.nsIInterfaceRequestor)
       .getInterface(Ci.nsISelectionDisplay)
       .QueryInterface(Ci.nsISelectionController);
-  },
+  }
 
   /**
    * A shortcut to the nsIWebBrowserFind for the content.
    */
   get webBrowserFind() {
-    return docShell
+    return this.docShell
       .QueryInterface(Ci.nsIInterfaceRequestor)
       .getInterface(Ci.nsIWebBrowserFind);
-  },
-
-  /**
-   * Called when the parent sends a message to view some source code.
-   *
-   * @param URL (required)
-   *        The URL string of the source to be shown.
-   * @param outerWindowID (optional)
-   *        The outerWindowID of the content window that has hosted
-   *        the document, in case we want to retrieve it from the network
-   *        cache.
-   * @param lineNumber (optional)
-   *        The line number to focus as soon as the source has finished
-   *        loading.
-   */
-  viewSource(URL, outerWindowID, lineNumber) {
-    let pageDescriptor, forcedCharSet;
-
-    if (outerWindowID) {
-      let contentWindow = Services.wm.getOuterWindowWithId(outerWindowID);
-      let otherDocShell = contentWindow.docShell;
-
-      try {
-        pageDescriptor = otherDocShell.QueryInterface(Ci.nsIWebPageDescriptor)
-          .currentDescriptor;
-      } catch (e) {
-        // We couldn't get the page descriptor, so we'll probably end up re-retrieving
-        // this document off of the network.
-      }
-
-      let utils = contentWindow.windowUtils;
-      let doc = contentWindow.document;
-      forcedCharSet = utils.docCharsetIsForced ? doc.characterSet : null;
-    }
-
-    this.loadSource(URL, pageDescriptor, lineNumber, forcedCharSet);
-  },
-
-  /**
-   * Common utility function used by both the current and deprecated APIs
-   * for loading source.
-   *
-   * @param URL (required)
-   *        The URL string of the source to be shown.
-   * @param pageDescriptor (optional)
-   *        The currentDescriptor off of an nsIWebPageDescriptor, in the
-   *        event that the caller wants to try to load the source out of
-   *        the network cache.
-   * @param lineNumber (optional)
-   *        The line number to focus as soon as the source has finished
-   *        loading.
-   * @param forcedCharSet (optional)
-   *        The document character set to use instead of the default one.
-   */
-  loadSource(URL, pageDescriptor, lineNumber, forcedCharSet) {
-    const viewSrcURL = "view-source:" + URL;
-
-    if (forcedCharSet) {
-      try {
-        docShell.charset = forcedCharSet;
-      } catch (e) {
-        /* invalid charset */
-      }
-    }
-
-    if (lineNumber && lineNumber > 0) {
-      let doneLoading = event => {
-        // Ignore possible initial load of about:blank
-        if (this.isAboutBlank || !content.document.body) {
-          return;
-        }
-        this.goToLine(lineNumber);
-        removeEventListener("pageshow", doneLoading);
-      };
-
-      addEventListener("pageshow", doneLoading);
-    }
-
-    if (!pageDescriptor) {
-      this.loadSourceFromURL(viewSrcURL);
-      return;
-    }
-
-    try {
-      let pageLoader = docShell.QueryInterface(Ci.nsIWebPageDescriptor);
-      pageLoader.loadPage(
-        pageDescriptor,
-        Ci.nsIWebPageDescriptor.DISPLAY_AS_SOURCE
-      );
-    } catch (e) {
-      // We were not able to load the source from the network cache.
-      this.loadSourceFromURL(viewSrcURL);
-      return;
-    }
-
-    let shEntrySource = pageDescriptor.QueryInterface(Ci.nsISHEntry);
-    let shistory = docShell.QueryInterface(Ci.nsIWebNavigation).sessionHistory
-      .legacySHistory;
-    let shEntry = shistory.createEntry();
-    shEntry.URI = Services.io.newURI(viewSrcURL);
-    shEntry.title = viewSrcURL;
-    let systemPrincipal = Services.scriptSecurityManager.getSystemPrincipal();
-    shEntry.triggeringPrincipal = systemPrincipal;
-    shEntry.setLoadTypeAsHistory();
-    shEntry.cacheKey = shEntrySource.cacheKey;
-    shistory.addEntry(shEntry, true);
-  },
-
-  /**
-   * Load some URL in the browser.
-   *
-   * @param URL
-   *        The URL string to load.
-   */
-  loadSourceFromURL(URL) {
-    let loadFlags = Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
-    let webNav = docShell.QueryInterface(Ci.nsIWebNavigation);
-    let loadURIOptions = {
-      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
-      loadFlags,
-    };
-    webNav.loadURI(URL, loadURIOptions);
-  },
+  }
 
   /**
    * This handler is for click events from:
@@ -313,11 +134,11 @@ var ViewSourceContent = {
     let target = event.originalTarget;
     // Check for content menu actions
     if (target.id) {
-      this.contextMenuItems.forEach(itemSpec => {
+      gContextMenuItems.forEach(itemSpec => {
         if (itemSpec.id !== target.id) {
           return;
         }
-        itemSpec.handler.call(this, event);
+        itemSpec.handler(this);
         event.stopPropagation();
       });
     }
@@ -334,10 +155,10 @@ var ViewSourceContent = {
 
       if (target == errorDoc.getElementById("goBackButton")) {
         // Instead of loading some safe page, just close the window
-        sendAsyncMessage("ViewSource:Close");
+        this.sendAsyncMessage("ViewSource:Close");
       }
     }
-  },
+  }
 
   /**
    * Handler for the pageshow event.
@@ -346,57 +167,27 @@ var ViewSourceContent = {
    *        The pageshow event being handled.
    */
   onPageShow(event) {
-    content.focus();
+    this.contentWindow.focus();
 
     // If we need to draw the selection, wait until an actual view source page
     // has loaded, instead of about:blank.
     if (
-      this.needsDrawSelection &&
-      content.document.documentURI.startsWith("view-source:")
+      gNeedsDrawSelection &&
+      this.document.documentURI.startsWith("view-source:")
     ) {
-      this.needsDrawSelection = false;
+      gNeedsDrawSelection = false;
       this.drawSelection();
     }
 
-    if (content.document.body) {
+    if (gInitialLineNumber >= 0) {
+      this.goToLine(gInitialLineNumber);
+      gInitialLineNumber = -1;
+    }
+
+    if (this.document.body) {
       this.injectContextMenu();
     }
-
-    sendAsyncMessage("ViewSource:SourceLoaded");
-  },
-
-  /**
-   * Handler for the pagehide event.
-   *
-   * @param event
-   *        The pagehide event being handled.
-   */
-  onPageHide(event) {
-    sendAsyncMessage("ViewSource:SourceUnloaded");
-  },
-
-  onContextMenu(event) {
-    let node = event.target;
-
-    let result = {
-      isEmail: false,
-      isLink: false,
-      href: "",
-      // We have to pass these in the event that we're running in
-      // a remote browser, so that ViewSourceChrome knows where to
-      // open the context menu.
-      screenX: event.screenX,
-      screenY: event.screenY,
-    };
-
-    if (node && node.localName == "a") {
-      result.isLink = node.href.startsWith("view-source:");
-      result.isEmail = node.href.startsWith("mailto:");
-      result.href = node.href.substring(node.href.indexOf(":") + 1);
-    }
-
-    sendSyncMessage("ViewSource:ContextMenuOpening", result);
-  },
+  }
 
   /**
    * Attempts to go to a particular line in the source code being
@@ -409,7 +200,7 @@ var ViewSourceContent = {
    *        The line number to attempt to go to.
    */
   goToLine(lineNumber) {
-    let body = content.document.body;
+    let body = this.document.body;
 
     // The source document is made up of a number of pre elements with
     // id attributes in the format <pre id="line123">, meaning that
@@ -439,11 +230,11 @@ var ViewSourceContent = {
     let found = this.findLocation(pre, lineNumber, null, -1, false, result);
 
     if (!found) {
-      sendAsyncMessage("ViewSource:GoToLine:Failed");
+      this.sendAsyncMessage("ViewSource:GoToLine:Failed");
       return;
     }
 
-    let selection = content.getSelection();
+    let selection = this.document.defaultView.getSelection();
     selection.removeAllRanges();
 
     // In our case, the range's startOffset is after "\n" on the previous line.
@@ -484,8 +275,8 @@ var ViewSourceContent = {
       true
     );
 
-    sendAsyncMessage("ViewSource:GoToLine:Success", { lineNumber });
-  },
+    this.sendAsyncMessage("ViewSource:GoToLine:Success", { lineNumber });
+  }
 
   /**
    * Some old code from the original view source implementation. Original
@@ -514,7 +305,7 @@ var ViewSourceContent = {
     let curLine = pre.id ? parseInt(pre.id.substring(4)) : 1;
 
     // Walk through each of the text nodes and count newlines.
-    let treewalker = content.document.createTreeWalker(
+    let treewalker = this.document.createTreeWalker(
       pre,
       NodeFilter.SHOW_TEXT,
       null
@@ -573,7 +364,7 @@ var ViewSourceContent = {
             break;
           }
         } else if (curLine == lineNumber && !("range" in result)) {
-          result.range = content.document.createRange();
+          result.range = this.document.createRange();
           result.range.setStart(textNode, curPos);
 
           // This will always be overridden later, except when we look for
@@ -589,17 +380,17 @@ var ViewSourceContent = {
     }
 
     return found || "range" in result;
-  },
+  }
 
   /**
    * Toggles the "wrap" class on the document body, which sets whether
    * or not long lines are wrapped.  Notifies parent to update the pref.
    */
   toggleWrapping() {
-    let body = content.document.body;
+    let body = this.document.body;
     let state = body.classList.toggle("wrap");
-    sendAsyncMessage("ViewSource:StoreWrapping", { state });
-  },
+    this.sendAsyncMessage("ViewSource:StoreWrapping", { state });
+  }
 
   /**
    * Toggles the "highlight" class on the document body, which sets whether
@@ -607,32 +398,10 @@ var ViewSourceContent = {
    * pref.
    */
   toggleSyntaxHighlighting() {
-    let body = content.document.body;
+    let body = this.document.body;
     let state = body.classList.toggle("highlight");
-    sendAsyncMessage("ViewSource:StoreSyntaxHighlighting", { state });
-  },
-
-  /**
-   * Loads a view source selection showing the given view-source url and
-   * highlight the selection.
-   *
-   * @param uri view-source uri to show
-   * @param drawSelection true to highlight the selection
-   * @param baseURI base URI of the original document
-   */
-  viewSourceWithSelection(uri, drawSelection, baseURI) {
-    this.needsDrawSelection = drawSelection;
-
-    // all our content is held by the data:URI and URIs are internally stored as utf-8 (see nsIURI.idl)
-    let loadFlags = Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
-    let webNav = docShell.QueryInterface(Ci.nsIWebNavigation);
-    let loadURIOptions = {
-      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
-      loadFlags,
-      baseURI: Services.io.newURI(baseURI),
-    };
-    webNav.loadURI(uri, loadURIOptions);
-  },
+    this.sendAsyncMessage("ViewSource:StoreSyntaxHighlighting", { state });
+  }
 
   /**
    * Using special markers left in the serialized source, this helper makes the
@@ -640,7 +409,7 @@ var ViewSourceContent = {
    * selected on the inflated view-source DOM.
    */
   drawSelection() {
-    content.document.title = this.bundle.GetStringFromName(
+    this.document.title = this.bundle.GetStringFromName(
       "viewSelectionSourceTitle"
     );
 
@@ -677,7 +446,7 @@ var ViewSourceContent = {
     var startLength = MARK_SELECTION_START.length;
     findInst.findNext();
 
-    var selection = content.getSelection();
+    var selection = this.document.defaultView.getSelection();
     if (!selection.rangeCount) {
       return;
     }
@@ -732,44 +501,13 @@ var ViewSourceContent = {
     findInst.wrapFind = wrapFind;
     findInst.findBackwards = findBackwards;
     findInst.searchString = searchString;
-  },
-
-  /**
-   * In-page context menu items that are injected after page load.
-   */
-  contextMenuItems: [
-    {
-      id: "goToLine",
-      accesskey: true,
-      handler() {
-        sendAsyncMessage("ViewSource:PromptAndGoToLine");
-      },
-    },
-    {
-      id: "wrapLongLines",
-      get checked() {
-        return Services.prefs.getBoolPref("view_source.wrap_long_lines");
-      },
-      handler() {
-        this.toggleWrapping();
-      },
-    },
-    {
-      id: "highlightSyntax",
-      get checked() {
-        return Services.prefs.getBoolPref("view_source.syntax_highlight");
-      },
-      handler() {
-        this.toggleSyntaxHighlighting();
-      },
-    },
-  ],
+  }
 
   /**
    * Add context menu items for view source specific actions.
    */
   injectContextMenu() {
-    let doc = content.document;
+    let doc = this.document;
 
     let menu = doc.createElementNS(NS_XHTML, "menu");
     menu.setAttribute("type", "context");
@@ -777,7 +515,7 @@ var ViewSourceContent = {
     doc.body.appendChild(menu);
     doc.body.setAttribute("contextmenu", "actions");
 
-    this.contextMenuItems.forEach(itemSpec => {
+    gContextMenuItems.forEach(itemSpec => {
       let item = doc.createElementNS(NS_XHTML, "menuitem");
       item.setAttribute("id", itemSpec.id);
       let labelName = `context_${itemSpec.id}_label`;
@@ -797,14 +535,14 @@ var ViewSourceContent = {
     });
 
     this.updateContextMenu();
-  },
+  }
 
   /**
    * Update state of checkbox-style context menu items.
    */
   updateContextMenu() {
-    let doc = content.document;
-    this.contextMenuItems.forEach(itemSpec => {
+    let doc = this.document;
+    gContextMenuItems.forEach(itemSpec => {
       if (!("checked" in itemSpec)) {
         return;
       }
@@ -815,6 +553,5 @@ var ViewSourceContent = {
         item.removeAttribute("checked");
       }
     });
-  },
-};
-ViewSourceContent.init();
+  }
+}
diff --git a/toolkit/actors/ViewSourcePageParent.jsm b/toolkit/actors/ViewSourcePageParent.jsm
new file mode 100644
index 000000000000..4070431a922e
--- /dev/null
+++ b/toolkit/actors/ViewSourcePageParent.jsm
@@ -0,0 +1,159 @@
+// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+ChromeUtils.defineModuleGetter(
+  this,
+  "Services",
+  "resource://gre/modules/Services.jsm"
+);
+
+const BUNDLE_URL = "chrome://global/locale/viewSource.properties";
+
+var EXPORTED_SYMBOLS = ["ViewSourcePageParent"];
+
+/**
+ * ViewSourcePageParent manages the view source <browser> from the chrome side.
+ */
+class ViewSourcePageParent extends JSWindowActorParent {
+  constructor() {
+    super();
+
+    /**
+     * Holds the value of the last line found via the "Go to line"
+     * command, to pre-populate the prompt the next time it is
+     * opened.
+     */
+    this.lastLineFound = null;
+  }
+
+  /**
+   * Anything added to the messages array will get handled here, and should
+   * get dispatched to a specific function for the message name.
+   */
+  receiveMessage(message) {
+    let data = message.data;
+
+    switch (message.name) {
+      case "ViewSource:PromptAndGoToLine":
+        this.promptAndGoToLine();
+        break;
+      case "ViewSource:GoToLine:Success":
+        this.onGoToLineSuccess(data.lineNumber);
+        break;
+      case "ViewSource:GoToLine:Failed":
+        this.onGoToLineFailed();
+        break;
+      case "ViewSource:StoreWrapping":
+        this.storeWrapping(data.state);
+        break;
+      case "ViewSource:StoreSyntaxHighlighting":
+        this.storeSyntaxHighlighting(data.state);
+        break;
+    }
+  }
+
+  /**
+   * A getter for the view source string bundle.
+   */
+  get bundle() {
+    if (this._bundle) {
+      return this._bundle;
+    }
+    return (this._bundle = Services.strings.createBundle(BUNDLE_URL));
+  }
+
+  /**
+   * Opens the "Go to line" prompt for a user to hop to a particular line
+   * of the source code they're viewing. This will keep prompting until the
+   * user either cancels out of the prompt, or enters a valid line number.
+   */
+  promptAndGoToLine() {
+    let input = { value: this.lastLineFound };
+    let window = Services.wm.getMostRecentWindow(null);
+
+    let ok = Services.prompt.prompt(
+      window,
+      this.bundle.GetStringFromName("goToLineTitle"),
+      this.bundle.GetStringFromName("goToLineText"),
+      input,
+      null,
+      { value: 0 }
+    );
+
+    if (!ok) {
+      return;
+    }
+
+    let line = parseInt(input.value, 10);
+
+    if (!(line > 0)) {
+      Services.prompt.alert(
+        window,
+        this.bundle.GetStringFromName("invalidInputTitle"),
+        this.bundle.GetStringFromName("invalidInputText")
+      );
+      this.promptAndGoToLine();
+    } else {
+      this.goToLine(line);
+    }
+  }
+
+  /**
+   * Go to a particular line of the source code. This act is asynchronous.
+   *
+   * @param lineNumber
+   *        The line number to try to go to to.
+   */
+  goToLine(lineNumber) {
+    this.sendAsyncMessage("ViewSource:GoToLine", { lineNumber });
+  }
+
+  /**
+   * Called when the frame script reports that a line was successfully gotten
+   * to.
+   *
+   * @param lineNumber
+   *        The line number that we successfully got to.
+   */
+  onGoToLineSuccess(lineNumber) {
+    // We'll pre-populate the "Go to line" prompt with this value the next
+    // time it comes up.
+    this.lastLineFound = lineNumber;
+  }
+
+  /**
+   * Called when the child reports that we failed to go to a particular
+   * line. This informs the user that their selection was likely out of range,
+   * and then reprompts the user to try again.
+   */
+  onGoToLineFailed() {
+    let window = Services.wm.getMostRecentWindow(null);
+    Services.prompt.alert(
+      window,
+      this.bundle.GetStringFromName("outOfRangeTitle"),
+      this.bundle.GetStringFromName("outOfRangeText")
+    );
+    this.promptAndGoToLine();
+  }
+
+  /**
+   * Update the wrapping pref based on the child's current state.
+   * @param state
+   *        Whether wrapping is currently enabled in the child.
+   */
+  storeWrapping(state) {
+    Services.prefs.setBoolPref("view_source.wrap_long_lines", state);
+  }
+
+  /**
+   * Update the syntax highlighting pref based on the child's current state.
+   * @param state
+   *        Whether syntax highlighting is currently enabled in the child.
+   */
+  storeSyntaxHighlighting(state) {
+    Services.prefs.setBoolPref("view_source.syntax_highlight", state);
+  }
+}
diff --git a/toolkit/actors/moz.build b/toolkit/actors/moz.build
index d2da96b9d535..a70e4e1814a7 100644
--- a/toolkit/actors/moz.build
+++ b/toolkit/actors/moz.build
@@ -48,11 +48,13 @@ FINAL_TARGET_FILES.actors += [
     'PrintingChild.jsm',
     'PurgeSessionHistoryChild.jsm',
     'SelectChild.jsm',
-    'SelectionSourceChild.jsm',
     'SelectParent.jsm',
     'ThumbnailsChild.jsm',
     'UAWidgetsChild.jsm',
     'UnselectedTabHoverChild.jsm',
+    'ViewSourceChild.jsm',
+    'ViewSourcePageChild.jsm',
+    'ViewSourcePageParent.jsm',
     'WebChannelChild.jsm',
     'WebChannelParent.jsm',
     'WebNavigationChild.jsm',
diff --git a/toolkit/components/viewsource/ViewSourceBrowser.jsm b/toolkit/components/viewsource/ViewSourceBrowser.jsm
deleted file mode 100644
index 17f83c0bc259..000000000000
--- a/toolkit/components/viewsource/ViewSourceBrowser.jsm
+++ /dev/null
@@ -1,335 +0,0 @@
-// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
-
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-ChromeUtils.defineModuleGetter(
-  this,
-  "Services",
-  "resource://gre/modules/Services.jsm"
-);
-
-const BUNDLE_URL = "chrome://global/locale/viewSource.properties";
-
-const FRAME_SCRIPT = "chrome://global/content/viewSource-content.js";
-
-var EXPORTED_SYMBOLS = ["ViewSourceBrowser"];
-
-// Keep a set of browsers we've seen before, so we can load our frame script as
-// needed into any new ones.
-var gKnownBrowsers = new WeakSet();
-
-/**
- * ViewSourceBrowser manages the view source <browser> from the chrome side.
- * It's companion frame script, viewSource-content.js, needs to be loaded as a
- * frame script into the browser being managed.
- *
- * For a view source tab (or some other non-window case), an instance of this is
- * created by viewSourceUtils.js to wrap the <browser>.  The frame script will
- * be loaded by this module at construction time.
- */
-function ViewSourceBrowser(aBrowser) {
-  this._browser = aBrowser;
-  this.init();
-}
-
-ViewSourceBrowser.prototype = {
-  /**
-   * The <browser> that will be displaying the view source content.
-   */
-  get browser() {
-    return this._browser;
-  },
-
-  /**
-   * Holds the value of the last line found via the "Go to line"
-   * command, to pre-populate the prompt the next time it is
-   * opened.
-   */
-  lastLineFound: null,
-
-  /**
-   * These are the messages that ViewSourceBrowser will listen for
-   * from the frame script it injects. Any message names added here
-   * will automatically have ViewSourceBrowser listen for those messages,
-   * and remove the listeners on teardown.
-   */
-  messages: [
-    "ViewSource:PromptAndGoToLine",
-    "ViewSource:GoToLine:Success",
-    "ViewSource:GoToLine:Failed",
-    "ViewSource:StoreWrapping",
-    "ViewSource:StoreSyntaxHighlighting",
-  ],
-
-  /**
-   * This should be called as soon as the script loads. When this function
-   * executes, we can assume the DOM content has not yet loaded.
-   */
-  init() {
-    this.messages.forEach(msgName => {
-      this.mm.addMessageListener(msgName, this);
-    });
-
-    this.loadFrameScript();
-  },
-
-  /**
-   * This should be called when the window is closing. This function should
-   * clean up event and message listeners.
-   */
-  uninit() {
-    this.messages.forEach(msgName => {
-      this.mm.removeMessageListener(msgName, this);
-    });
-  },
-
-  /**
-   * For a new browser we've not seen before, load the frame script.
-   */
-  loadFrameScript() {
-    // Check for a browser first. There won't be one for the window case
-    // (still used by other applications like Thunderbird), as the element
-    // does not exist until the XUL document loads.
-    if (!this.browser) {
-      return;
-    }
-    if (!gKnownBrowsers.has(this.browser)) {
-      gKnownBrowsers.add(this.browser);
-      this.mm.loadFrameScript(FRAME_SCRIPT, false);
-    }
-  },
-
-  /**
-   * Anything added to the messages array will get handled here, and should
-   * get dispatched to a specific function for the message name.
-   */
-  receiveMessage(message) {
-    let data = message.data;
-
-    switch (message.name) {
-      case "ViewSource:PromptAndGoToLine":
-        this.promptAndGoToLine();
-        break;
-      case "ViewSource:GoToLine:Success":
-        this.onGoToLineSuccess(data.lineNumber);
-        break;
-      case "ViewSource:GoToLine:Failed":
-        this.onGoToLineFailed();
-        break;
-      case "ViewSource:StoreWrapping":
-        this.storeWrapping(data.state);
-        break;
-      case "ViewSource:StoreSyntaxHighlighting":
-        this.storeSyntaxHighlighting(data.state);
-        break;
-    }
-  },
-
-  /**
-   * Getter for the message manager of the view source browser.
-   */
-  get mm() {
-    return this.browser.messageManager;
-  },
-
-  /**
-   * Send a message to the view source browser.
-   */
-  sendAsyncMessage(...args) {
-    this.browser.messageManager.sendAsyncMessage(...args);
-  },
-
-  /**
-   * A getter for the view source string bundle.
-   */
-  get bundle() {
-    if (this._bundle) {
-      return this._bundle;
-    }
-    return (this._bundle = Services.strings.createBundle(BUNDLE_URL));
-  },
-
-  /**
-   * Loads the source for a URL while applying some optional features if
-   * enabled.
-   *
-   * For view source in a specific browser, this is manually called after
-   * this object is constructed.
-   *
-   * This takes a single object argument containing:
-   *
-   *   URL (required):
-   *     A string URL for the page we'd like to view the source of.
-   *   browser:
-   *     The browser containing the document that we would like to view the
-   *     source of. This argument is optional if outerWindowID is not passed.
-   *   outerWindowID (optional):
-   *     The outerWindowID of the content window containing the document that
-   *     we want to view the source of. This is the only way of attempting to
-   *     load the source out of the network cache.
-   *   lineNumber (optional):
-   *     The line number to focus on once the source is loaded.
-   */
-  loadViewSource({ URL, browser, outerWindowID, lineNumber }) {
-    if (!URL) {
-      throw new Error("Must supply a URL when opening view source.");
-    }
-
-    if (browser) {
-      this.browser.sameProcessAsFrameLoader = browser.frameLoader;
-
-      // If we're dealing with a remote browser, then the browser
-      // for view source needs to be remote as well.
-      this.updateBrowserRemoteness(browser.remoteType);
-    } else if (outerWindowID) {
-      throw new Error("Must supply the browser if passing the outerWindowID");
-    }
-
-    this.sendAsyncMessage("ViewSource:LoadSource", {
-      URL,
-      outerWindowID,
-      lineNumber,
-    });
-  },
-
-  /**
-   * Loads a view source selection showing the given view-source url and
-   * highlight the selection.
-   *
-   * @param uri view-source uri to show
-   * @param drawSelection true to highlight the selection
-   * @param baseURI base URI of the original document
-   */
-  loadViewSourceFromSelection(URL, drawSelection, baseURI) {
-    this.sendAsyncMessage("ViewSource:LoadSourceWithSelection", {
-      URL,
-      drawSelection,
-      baseURI,
-    });
-  },
-
-  /**
-   * Updates the "remote" attribute of the view source browser. This
-   * will remove the browser from the DOM, and then re-add it in the
-   * same place it was taken from.
-   *
-   * @param shouldBeRemote
-   *        True if the browser should be made remote. If the browsers
-   *        remoteness already matches this value, this function does
-   *        nothing.
-   * @param remoteType
-   *        The type of remote browser process.
-   */
-  updateBrowserRemoteness(remoteType) {
-    if (this.browser.remoteType != remoteType) {
-      // In this base case, where we are handed a <browser> someone else is
-      // managing, we don't know for sure that it's safe to toggle remoteness.
-      // For view source in a window, this is overridden to actually do the
-      // flip if needed.
-      throw new Error("View source browser's remoteness mismatch");
-    }
-  },
-
-  /**
-   * Opens the "Go to line" prompt for a user to hop to a particular line
-   * of the source code they're viewing. This will keep prompting until the
-   * user either cancels out of the prompt, or enters a valid line number.
-   */
-  promptAndGoToLine() {
-    let input = { value: this.lastLineFound };
-    let window = Services.wm.getMostRecentWindow(null);
-
-    let ok = Services.prompt.prompt(
-      window,
-      this.bundle.GetStringFromName("goToLineTitle"),
-      this.bundle.GetStringFromName("goToLineText"),
-      input,
-      null,
-      { value: 0 }
-    );
-
-    if (!ok) {
-      return;
-    }
-
-    let line = parseInt(input.value, 10);
-
-    if (!(line > 0)) {
-      Services.prompt.alert(
-        window,
-        this.bundle.GetStringFromName("invalidInputTitle"),
-        this.bundle.GetStringFromName("invalidInputText")
-      );
-      this.promptAndGoToLine();
-    } else {
-      this.goToLine(line);
-    }
-  },
-
-  /**
-   * Go to a particular line of the source code. This act is asynchronous.
-   *
-   * @param lineNumber
-   *        The line number to try to go to to.
-   */
-  goToLine(lineNumber) {
-    this.sendAsyncMessage("ViewSource:GoToLine", { lineNumber });
-  },
-
-  /**
-   * Called when the frame script reports that a line was successfully gotten
-   * to.
-   *
-   * @param lineNumber
-   *        The line number that we successfully got to.
-   */
-  onGoToLineSuccess(lineNumber) {
-    // We'll pre-populate the "Go to line" prompt with this value the next
-    // time it comes up.
-    this.lastLineFound = lineNumber;
-  },
-
-  /**
-   * Called when the frame script reports that we failed to go to a particular
-   * line. This informs the user that their selection was likely out of range,
-   * and then reprompts the user to try again.
-   */
-  onGoToLineFailed() {
-    let window = Services.wm.getMostRecentWindow(null);
-    Services.prompt.alert(
-      window,
-      this.bundle.GetStringFromName("outOfRangeTitle"),
-      this.bundle.GetStringFromName("outOfRangeText")
-    );
-    this.promptAndGoToLine();
-  },
-
-  /**
-   * Update the wrapping pref based on the child's current state.
-   * @param state
-   *        Whether wrapping is currently enabled in the child.
-   */
-  storeWrapping(state) {
-    Services.prefs.setBoolPref("view_source.wrap_long_lines", state);
-  },
-
-  /**
-   * Update the syntax highlighting pref based on the child's current state.
-   * @param state
-   *        Whether syntax highlighting is currently enabled in the child.
-   */
-  storeSyntaxHighlighting(state) {
-    Services.prefs.setBoolPref("view_source.syntax_highlight", state);
-  },
-};
-
-/**
- * Helper to decide if a URI maps to view source content.
- * @param uri
- *        String containing the URI
- */
-ViewSourceBrowser.isViewSource = function(uri) {
-  return uri.startsWith("view-source:");
-};
diff --git a/toolkit/components/viewsource/content/viewSourceUtils.js b/toolkit/components/viewsource/content/viewSourceUtils.js
index 42ee103f19ab..da9efd0d55b8 100644
--- a/toolkit/components/viewsource/content/viewSourceUtils.js
+++ b/toolkit/components/viewsource/content/viewSourceUtils.js
@@ -14,11 +14,6 @@
 
 var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 
-ChromeUtils.defineModuleGetter(
-  this,
-  "ViewSourceBrowser",
-  "resource://gre/modules/ViewSourceBrowser.jsm"
-);
 ChromeUtils.defineModuleGetter(
   this,
   "PrivateBrowsingUtils",
@@ -30,6 +25,11 @@ var gViewSourceUtils = {
   mnsIWebProgress: Ci.nsIWebProgress,
   mnsIWebPageDescriptor: Ci.nsIWebPageDescriptor,
 
+  // Get the ViewSource actor for a browsing context.
+  getViewSourceActor(aBrowsingContext) {
+    return aBrowsingContext.currentWindowGlobal.getActor("ViewSource");
+  },
+
   /**
    * Opens the view source window.
    *
@@ -106,9 +106,41 @@ var gViewSourceUtils = {
    *        lineNumber (optional):
    *          The line number to focus on once the source is loaded.
    */
-  viewSourceInBrowser(aArgs) {
-    let viewSourceBrowser = new ViewSourceBrowser(aArgs.viewSourceBrowser);
-    viewSourceBrowser.loadViewSource(aArgs);
+  viewSourceInBrowser({
+    URL,
+    viewSourceBrowser,
+    browser,
+    outerWindowID,
+    lineNumber,
+  }) {
+    if (!URL) {
+      throw new Error("Must supply a URL when opening view source.");
+    }
+
+    if (browser) {
+      viewSourceBrowser.sameProcessAsFrameLoader = browser.frameLoader;
+
+      // If we're dealing with a remote browser, then the browser
+      // for view source needs to be remote as well.
+      if (viewSourceBrowser.remoteType != browser.remoteType) {
+        // In this base case, where we are handed a <browser> someone else is
+        // managing, we don't know for sure that it's safe to toggle remoteness.
+        // For view source in a window, this is overridden to actually do the
+        // flip if needed.
+        throw new Error("View source browser's remoteness mismatch");
+      }
+    } else if (outerWindowID) {
+      throw new Error("Must supply the browser if passing the outerWindowID");
+    }
+
+    let viewSourceActor = this.getViewSourceActor(
+      viewSourceBrowser.browsingContext
+    );
+    viewSourceActor.sendAsyncMessage("ViewSource:LoadSource", {
+      URL,
+      outerWindowID,
+      lineNumber,
+    });
   },
 
   /**
@@ -116,31 +148,21 @@ var gViewSourceUtils = {
    * <browser>.  This allows for non-window display methods, such as a tab from
    * Firefox.
    *
-   * @param aViewSourceInBrowser
-   *        The browser containing the page to view the source of.
+   * @param aBrowsingContext:
+   *        The child browsing context containing the document to view the source of.
    * @param aGetBrowserFn
    *        A function that will return a browser to open the source in.
    */
-  viewPartialSourceInBrowser(aViewSourceInBrowser, aGetBrowserFn) {
-    let mm = aViewSourceInBrowser.messageManager;
-    mm.addMessageListener("ViewSource:GetSelectionDone", function gotSelection(
-      message
-    ) {
-      mm.removeMessageListener("ViewSource:GetSelectionDone", gotSelection);
+  async viewPartialSourceInBrowser(aBrowsingContext, aGetBrowserFn) {
+    let sourceActor = this.getViewSourceActor(aBrowsingContext);
+    if (sourceActor) {
+      let data = await sourceActor.sendQuery("ViewSource:GetSelection", {});
 
-      if (!message.data) {
-        return;
-      }
-
-      let viewSourceBrowser = new ViewSourceBrowser(aGetBrowserFn());
-      viewSourceBrowser.loadViewSourceFromSelection(
-        message.data.uri,
-        message.data.drawSelection,
-        message.data.baseURI
+      let targetActor = this.getViewSourceActor(
+        aGetBrowserFn().browsingContext
       );
-    });
-
-    mm.sendAsyncMessage("ViewSource:GetSelection");
+      targetActor.sendAsyncMessage("ViewSource:LoadSourceWithSelection", data);
+    }
   },
 
   buildEditorArgs(aPath, aLineNumber) {
diff --git a/toolkit/components/viewsource/jar.mn b/toolkit/components/viewsource/jar.mn
index 7585980ea6c7..e483f3080a4b 100644
--- a/toolkit/components/viewsource/jar.mn
+++ b/toolkit/components/viewsource/jar.mn
@@ -4,4 +4,3 @@
 
 toolkit.jar:
   content/global/viewSourceUtils.js         (content/viewSourceUtils.js)
-  content/global/viewSource-content.js      (content/viewSource-content.js)
diff --git a/toolkit/components/viewsource/moz.build b/toolkit/components/viewsource/moz.build
index aecd25682991..c13e61e30be7 100644
--- a/toolkit/components/viewsource/moz.build
+++ b/toolkit/components/viewsource/moz.build
@@ -9,9 +9,5 @@ MOCHITEST_CHROME_MANIFESTS += ['test/chrome.ini']
 
 JAR_MANIFESTS += ['jar.mn']
 
-EXTRA_JS_MODULES += [
-    'ViewSourceBrowser.jsm',
-]
-
 with Files('**'):
     BUG_COMPONENT = ('Toolkit', 'View Source')
diff --git a/toolkit/components/viewsource/test/browser/browser.ini b/toolkit/components/viewsource/test/browser/browser.ini
index 8b90795a2d0c..206ad969a897 100644
--- a/toolkit/components/viewsource/test/browser/browser.ini
+++ b/toolkit/components/viewsource/test/browser/browser.ini
@@ -9,5 +9,6 @@ support-files = head.js
 skip-if = (os == "win" && processor == "aarch64") # disabled on aarch64 due to 1531590
 [browser_gotoline.js]
 [browser_open_docgroup.js]
+[browser_partialsource.js]
 [browser_srcdoc.js]
 [browser_viewsourceprefs.js]
diff --git a/toolkit/components/viewsource/test/browser/browser_gotoline.js b/toolkit/components/viewsource/test/browser/browser_gotoline.js
index 2321b9371119..7837517ec64c 100644
--- a/toolkit/components/viewsource/test/browser/browser_gotoline.js
+++ b/toolkit/components/viewsource/test/browser/browser_gotoline.js
@@ -24,9 +24,13 @@ var checkViewSource = async function(aTab) {
   });
 
   for (let i = 1; i <= 3; i++) {
-    browser.messageManager.sendAsyncMessage("ViewSource:GoToLine", {
-      lineNumber: i,
-    });
+    browser.sendMessageToActor(
+      "ViewSource:GoToLine",
+      {
+        lineNumber: i,
+      },
+      "ViewSourcePage"
+    );
     await SpecialPowers.spawn(browser, [i], async function(i) {
       let selection = content.getSelection();
       Assert.equal(selection.toString(), "line " + i, "Correct text selected");
diff --git a/toolkit/components/viewsource/test/browser/browser_partialsource.js b/toolkit/components/viewsource/test/browser/browser_partialsource.js
new file mode 100644
index 000000000000..48b0adccc8eb
--- /dev/null
+++ b/toolkit/components/viewsource/test/browser/browser_partialsource.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+const frameSource =
+  "<a href='about:mozilla'>some text</a><a id='other' href='about:about'>other text</a>";
+const sources = [
+  `<html><iframe id="f" srcdoc="${frameSource}"></iframe></html>`,
+  `<html><iframe id="f" src="https://example.com/document-builder.sjs?html=${frameSource}"></iframe></html>`,
+];
+
+add_task(async function partial_source() {
+  for (let source of sources) {
+    let tab = await BrowserTestUtils.openNewForegroundTab(
+      gBrowser,
+      "data:text/html," + source
+    );
+
+    let frameBC = gBrowser.selectedBrowser.browsingContext.getChildren()[0];
+
+    await SpecialPowers.spawn(frameBC, [], () => {
+      let element = content.document.getElementById("other");
+      content.focus();
+      content.getSelection().selectAllChildren(element);
+    });
+
+    let sourceTab = await openViewPartialSource("#other", frameBC);
+
+    let browser = gBrowser.selectedBrowser;
+    let textContent = await SpecialPowers.spawn(browser, [], async function() {
+      return content.document.body.textContent;
+    });
+    is(
+      textContent,
+      '<a id="other" href="about:about">other text</a>',
+      "Correct content loaded"
+    );
+    let selection = await SpecialPowers.spawn(browser, [], async function() {
+      return String(content.getSelection());
+    });
+    is(selection, "other text", "Correct text selected");
+
+    gBrowser.removeTab(sourceTab);
+    gBrowser.removeTab(tab);
+  }
+});
diff --git a/toolkit/components/viewsource/test/browser/head.js b/toolkit/components/viewsource/test/browser/head.js
index c129dc62e51a..186a17c3e047 100644
--- a/toolkit/components/viewsource/test/browser/head.js
+++ b/toolkit/components/viewsource/test/browser/head.js
@@ -87,9 +87,13 @@ async function openViewSource() {
  * @param aCSSSelector - used to specify a node within the selection to
  *                       view the source of. It is expected that this node is
  *                       within an existing selection.
+ * @param aBrowsingContext - browsing context containing a subframe (optional).
  * @returns the new tab which shows the source.
  */
-async function openViewPartialSource(aCSSSelector) {
+async function openViewPartialSource(
+  aCSSSelector,
+  aBrowsingContext = gBrowser.selectedBrowser
+) {
   let contentAreaContextMenuPopup = document.getElementById(
     "contentAreaContextMenu"
   );
@@ -100,7 +104,7 @@ async function openViewPartialSource(aCSSSelector) {
   await BrowserTestUtils.synthesizeMouseAtCenter(
     aCSSSelector,
     { type: "contextmenu", button: 2 },
-    gBrowser.selectedBrowser
+    aBrowsingContext
   );
   await popupShownPromise;
 
@@ -161,13 +165,12 @@ async function openViewFrameSourceTab(aCSSSelector) {
  * complete.
  */
 function waitForSourceLoaded(tab) {
-  return new Promise(resolve => {
-    let mm = tab.linkedBrowser.messageManager;
-    mm.addMessageListener("ViewSource:SourceLoaded", function sourceLoaded() {
-      mm.removeMessageListener("ViewSource:SourceLoaded", sourceLoaded);
-      setTimeout(resolve, 0);
-    });
-  });
+  return BrowserTestUtils.waitForContentEvent(
+    tab.linkedBrowser,
+    "pageshow",
+    false,
+    event => String(event.target.location).startsWith("view-source")
+  );
 }
 
 /**
diff --git a/toolkit/modules/ActorManagerParent.jsm b/toolkit/modules/ActorManagerParent.jsm
index 0c19dd0d1f25..ba627c70f25b 100644
--- a/toolkit/modules/ActorManagerParent.jsm
+++ b/toolkit/modules/ActorManagerParent.jsm
@@ -300,6 +300,35 @@ let ACTORS = {
     allFrames: true,
   },
 
+  // This actor is available for all pages that one can
+  // view the source of, however it won't be created until a
+  // request to view the source is made via the message
+  // 'ViewSource:LoadSource' or 'ViewSource:LoadSourceWithSelection'.
+  ViewSource: {
+    child: {
+      moduleURI: "resource://gre/actors/ViewSourceChild.jsm",
+    },
+
+    allFrames: true,
+  },
+
+  // This actor is for the view-source page itself.
+  ViewSourcePage: {
+    parent: {
+      moduleURI: "resource://gre/actors/ViewSourcePageParent.jsm",
+    },
+    child: {
+      moduleURI: "resource://gre/actors/ViewSourcePageChild.jsm",
+      events: {
+        pageshow: { capture: true },
+        click: {},
+      },
+    },
+
+    matches: ["view-source:*"],
+    allFrames: true,
+  },
+
   WebChannel: {
     parent: {
       moduleURI: "resource://gre/actors/WebChannelParent.jsm",
@@ -485,13 +514,6 @@ let LEGACY_ACTORS = {
     },
   },
 
-  SelectionSource: {
-    child: {
-      module: "resource://gre/actors/SelectionSourceChild.jsm",
-      messages: ["ViewSource:GetSelection"],
-    },
-  },
-
   UnselectedTabHover: {
     child: {
       module: "resource://gre/actors/UnselectedTabHoverChild.jsm",