merge m-c to fx-team

browser/base/content/browser-thumbnails.js

@@ -25,11 +25,6 @@ let gBrowserThumbnails = {
    */
   _timeouts: null,
 
-  /**
-   * Cache for the PageThumbs module.
-   */
-  _pageThumbs: null,
-
   /**
    * List of tab events we want to listen for.
    */
@@ -52,9 +47,6 @@ let gBrowserThumbnails = {
     }, this);
 
     this._timeouts = new WeakMap();
-
-    XPCOMUtils.defineLazyModuleGetter(this, "_pageThumbs",
-      "resource:///modules/PageThumbs.jsm", "PageThumbs");
   },
 
   uninit: function Thumbnails_uninit() {
@@ -100,7 +92,7 @@ let gBrowserThumbnails = {
 
   _capture: function Thumbnails_capture(aBrowser) {
     if (this._shouldCapture(aBrowser))
-      this._pageThumbs.captureAndStore(aBrowser);
+      PageThumbs.captureAndStore(aBrowser);
   },
 
   _delayedCapture: function Thumbnails_delayedCapture(aBrowser) {

browser/base/content/browser.js

@@ -140,6 +140,9 @@ XPCOMUtils.defineLazyGetter(this, "Social", function() {
   return tmp.Social;
 });
 
+XPCOMUtils.defineLazyModuleGetter(this, "PageThumbs",
+  "resource:///modules/PageThumbs.jsm");
+
 #ifdef MOZ_SAFE_BROWSING
 XPCOMUtils.defineLazyGetter(this, "SafeBrowsing", function() {
   let tmp = {};

browser/base/content/tabbrowser.xml

@@ -3407,7 +3407,20 @@
         // Set the cursor to an arrow during tab drags.
         dt.mozCursor = "default";
 
-        let canvas = tabPreviews.capture(tab, false);
+        // Create a canvas to which we capture the current tab.
+        let canvas = document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
+        canvas.mozOpaque = true;
+
+        // We want drag images to be about 1/6th of the available screen width.
+        const widthFactor = 0.1739; // 1:5.75 inverse
+        canvas.width = Math.ceil(screen.availWidth * widthFactor);
+
+        // Maintain a 16:9 aspect ratio for drag images.
+        const aspectRatio = 0.5625; // 16:9 inverse
+        canvas.height = Math.round(canvas.width * aspectRatio);
+
+        let browser = tab.linkedBrowser;
+        PageThumbs.captureToCanvas(browser.contentWindow, canvas);
         dt.setDragImage(canvas, 0, 0);
 
         // _dragOffsetX/Y give the coordinates that the mouse should be

browser/components/thumbnails/PageThumbs.jsm

@@ -116,11 +116,26 @@ let PageThumbs = {
       return;
     }
 
-    let telemetryCaptureTime = new Date();
-    let [sw, sh, scale] = this._determineCropSize(aWindow);
-
     let canvas = this._createCanvas();
-    let ctx = canvas.getContext("2d");
+    this.captureToCanvas(aWindow, canvas);
+
+    // Fetch the canvas data on the next event loop tick so that we allow
+    // some event processing in between drawing to the canvas and encoding
+    // its data. We want to block the UI as short as possible. See bug 744100.
+    Services.tm.currentThread.dispatch(function () {
+      canvas.mozFetchAsStream(aCallback, this.contentType);
+    }.bind(this), Ci.nsIThread.DISPATCH_NORMAL);
+  },
+
+  /**
+   * Captures a thumbnail from a given window and draws it to the given canvas.
+   * @param aWindow The DOM window to capture a thumbnail from.
+   * @param aCanvas The canvas to draw to.
+   */
+  captureToCanvas: function PageThumbs_captureToCanvas(aWindow, aCanvas) {
+    let telemetryCaptureTime = new Date();
+    let [sw, sh, scale] = this._determineCropSize(aWindow, aCanvas);
+    let ctx = aCanvas.getContext("2d");
 
     // Scale the canvas accordingly.
     ctx.scale(scale, scale);
@@ -136,13 +151,6 @@ let PageThumbs = {
     let telemetry = Services.telemetry;
     telemetry.getHistogramById("FX_THUMBNAILS_CAPTURE_TIME_MS")
       .add(new Date() - telemetryCaptureTime);
-
-    // Fetch the canvas data on the next event loop tick so that we allow
-    // some event processing in between drawing to the canvas and encoding
-    // its data. We want to block the UI as short as possible. See bug 744100.
-    Services.tm.currentThread.dispatch(function () {
-      canvas.mozFetchAsStream(aCallback, this.contentType);
-    }.bind(this), Ci.nsIThread.DISPATCH_NORMAL);
   },
 
   /**
@@ -193,13 +201,14 @@ let PageThumbs = {
   /**
    * Determines the crop size for a given content window.
    * @param aWindow The content window.
+   * @param aCanvas The target canvas.
    * @return An array containing width, height and scale.
    */
-  _determineCropSize: function PageThumbs_determineCropSize(aWindow) {
+  _determineCropSize: function PageThumbs_determineCropSize(aWindow, aCanvas) {
     let sw = aWindow.innerWidth;
     let sh = aWindow.innerHeight;
 
-    let [thumbnailWidth, thumbnailHeight] = this._getThumbnailSize();
+    let {width: thumbnailWidth, height: thumbnailHeight} = aCanvas;
     let scale = Math.max(thumbnailWidth / sw, thumbnailHeight / sh);
     let scaledWidth = sw * scale;
     let scaledHeight = sh * scale;

browser/components/thumbnails/test/head.js

@@ -11,8 +11,6 @@ registerCleanupFunction(function () {
     gBrowser.removeTab(gBrowser.tabs[1]);
 });
 
-let cachedXULDocument;
-
 /**
  * Provide the default test function to start our test runner.
  */

browser/devtools/debugger/debugger-controller.js

@@ -51,15 +51,16 @@ let DebuggerController = {
     window.removeEventListener("DOMContentLoaded", this._startupDebugger, true);
 
     DebuggerView.initializePanes();
-    DebuggerView.initializeEditor();
+    DebuggerView.initializeEditor(function() {
-    DebuggerView.StackFrames.initialize();
+      DebuggerView.Scripts.initialize();
-    DebuggerView.Breakpoints.initialize();
+      DebuggerView.StackFrames.initialize();
-    DebuggerView.Properties.initialize();
+      DebuggerView.Breakpoints.initialize();
-    DebuggerView.Scripts.initialize();
+      DebuggerView.Properties.initialize();
-    DebuggerView.showCloseButton(!this._isRemoteDebugger && !this._isChromeDebugger);
+      DebuggerView.showCloseButton(!this._isRemoteDebugger && !this._isChromeDebugger);
 
-    this.dispatchEvent("Debugger:Loaded");
+      this.dispatchEvent("Debugger:Loaded");
-    this._connect();
+      this._connect();
+    }.bind(this));
   },
 
   /**
@@ -934,7 +935,7 @@ SourceScripts.prototype = {
 
     // Select the preferred script if one exists, the first entry otherwise.
     let preferredScriptUrl = DebuggerView.Scripts.preferredScriptUrl;
-    if (preferredScriptUrl) {
+    if (preferredScriptUrl && DebuggerView.Scripts.contains(preferredScriptUrl)) {
       DebuggerView.Scripts.selectScript(preferredScriptUrl);
     } else {
       DebuggerView.Scripts.selectIndex(0);

browser/devtools/debugger/debugger-view.js

@@ -32,8 +32,11 @@ let DebuggerView = {
 
   /**
    * Initializes the SourceEditor instance.
+   *
+   * @param function aCallback
+   *        Called after the editor finishes initializing.
    */
-  initializeEditor: function DV_initializeEditor() {
+  initializeEditor: function DV_initializeEditor(aCallback) {
     let placeholder = document.getElementById("editor");
 
     let config = {
@@ -45,7 +48,10 @@ let DebuggerView = {
     };
 
     this.editor = new SourceEditor();
-    this.editor.init(placeholder, config, this._onEditorLoad.bind(this));
+    this.editor.init(placeholder, config, function() {
+      this._onEditorLoad();
+      aCallback();
+    }.bind(this));
   },
 
   /**
@@ -474,7 +480,7 @@ ScriptsView.prototype = {
       for (let i = 0, l = scripts.itemCount; i < l; i++) {
         scripts.getItemAtIndex(i).hidden = false;
       }
-    } else {
+    } else if (this._prevSearchedFile !== file) {
       let found = false;
 
       for (let i = 0, l = scripts.itemCount; i < l; i++) {
@@ -502,15 +508,18 @@ ScriptsView.prototype = {
         scripts.removeAttribute("tooltiptext");
       }
     }
-    if (line > -1) {
+    if (this._prevSearchedLine !== line && line > -1) {
       editor.setCaretPosition(line - 1);
     }
-    if (token.length) {
+    if (this._prevSearchedToken !== token && token.length > 0) {
       let offset = editor.find(token, { ignoreCase: true });
       if (offset > -1) {
         editor.setSelection(offset, offset + token.length)
       }
     }
+    this._prevSearchedFile = file;
+    this._prevSearchedLine = line;
+    this._prevSearchedToken = token;
   },
 
   /**

browser/devtools/debugger/test/Makefile.in

@@ -44,6 +44,7 @@ MOCHITEST_BROWSER_TESTS = \
 	browser_dbg_stack-04.js \
 	browser_dbg_stack-05.js \
 	browser_dbg_location-changes.js \
+	browser_dbg_location-changes-new.js \
 	browser_dbg_location-changes-blank.js \
 	browser_dbg_script-switching.js \
 	browser_dbg_scripts-sorting.js \

browser/devtools/debugger/test/browser_dbg_location-changes-new.js

@@ -0,0 +1,91 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure that changing the tab location URL to a page with other scripts works.
+ */
+
+var gPane = null;
+var gTab = null;
+var gDebuggee = null;
+var gDebugger = null;
+
+function test()
+{
+  debug_tab_pane(STACK_URL, function(aTab, aDebuggee, aPane) {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPane = aPane;
+    gDebugger = gPane.contentWindow;
+
+    testSimpleCall();
+  });
+}
+
+function testSimpleCall() {
+  gDebugger.DebuggerController.activeThread.addOneTimeListener("framesadded", function() {
+    Services.tm.currentThread.dispatch({
+      run: function() {
+        var frames = gDebugger.DebuggerView.StackFrames._frames,
+            childNodes = frames.childNodes;
+
+        is(gDebugger.DebuggerController.activeThread.state, "paused",
+          "Should only be getting stack frames while paused.");
+
+        is(frames.querySelectorAll(".dbg-stackframe").length, 1,
+          "Should have only one frame.");
+
+        is(childNodes.length, frames.querySelectorAll(".dbg-stackframe").length,
+          "All children should be frames.");
+
+        isnot(gDebugger.DebuggerView.Scripts.selected, null,
+          "There should be a selected script.");
+        isnot(gDebugger.editor.getText().length, 0,
+          "The source editor should have some text displayed.");
+
+        testLocationChange();
+      }
+    }, 0);
+  });
+
+  gDebuggee.simpleCall();
+}
+
+function testLocationChange()
+{
+  gDebugger.DebuggerController.activeThread.resume(function() {
+    gDebugger.DebuggerController.client.addOneTimeListener("tabNavigated", function(aEvent, aPacket) {
+      ok(true, "tabNavigated event was fired.");
+      gDebugger.DebuggerController.client.addOneTimeListener("tabAttached", function(aEvent, aPacket) {
+        ok(true, "Successfully reattached to the tab again.");
+
+        // Wait for the initial resume...
+        gDebugger.gClient.addOneTimeListener("resumed", function() {
+          isnot(gDebugger.DebuggerView.Scripts.selected, null,
+            "There should be a selected script.");
+          isnot(gDebugger.editor.getText().length, 0,
+            "The source editor should have some text displayed.");
+
+          let menulist = gDebugger.DebuggerView.Scripts._scripts;
+          let noScripts = gDebugger.L10N.getStr("noScriptsText");
+          isnot(menulist.getAttribute("label"), noScripts,
+            "The menulist should not display a notice that there are no scripts availalble.");
+          isnot(menulist.getAttribute("tooltiptext"), "",
+            "The menulist should have a tooltip text attributed.");
+
+          closeDebuggerAndFinish();
+        });
+      });
+    });
+    content.location = EXAMPLE_URL + "browser_dbg_iframes.html";
+  });
+}
+
+registerCleanupFunction(function() {
+  removeTab(gTab);
+  gPane = null;
+  gTab = null;
+  gDebuggee = null;
+  gDebugger = null;
+});

browser/devtools/debugger/test/browser_dbg_scripts-searching-01.js

@@ -191,6 +191,11 @@ function clear() {
 
 function write(text) {
   clear();
+  append(text);
+}
+
+function append(text) {
+  gSearchBox.focus();
 
   for (let i = 0; i < text.length; i++) {
     EventUtils.sendChar(text[i]);

browser/devtools/debugger/test/browser_dbg_scripts-searching-02.js

@@ -96,6 +96,8 @@ function secondSearch() {
       window.removeEventListener(aEvent.type, _onEvent);
 
       executeSoon(function() {
+        append("#" + token);
+
         info("Editor caret position: " + gEditor.getCaretPosition().toSource() + "\n");
         ok(gEditor.getCaretPosition().line == 5 &&
            gEditor.getCaretPosition().col == 8 + token.length,
@@ -103,6 +105,49 @@ function secondSearch() {
         is(gScripts.visibleItemsCount, 1,
           "Not all the correct scripts are shown after the search. (2)");
 
+        waitForFirstScript();
+      });
+    }
+  });
+  gScripts.selectIndex(1);
+}
+
+function waitForFirstScript() {
+  window.addEventListener("Debugger:ScriptShown", function _onEvent(aEvent) {
+    info("Current script url:\n" + aEvent.detail.url + "\n");
+    info("Debugger editor text:\n" + gEditor.getText() + "\n");
+
+    let url = aEvent.detail.url;
+    if (url.indexOf("-01.js") != -1) {
+      window.removeEventListener(aEvent.type, _onEvent);
+
+      executeSoon(function() {
+        thirdSearch();
+      });
+    }
+  });
+  gScripts.selectIndex(0);
+}
+
+function thirdSearch() {
+  let token = "deb";
+
+  window.addEventListener("Debugger:ScriptShown", function _onEvent(aEvent) {
+    info("Current script url:\n" + aEvent.detail.url + "\n");
+    info("Debugger editor text:\n" + gEditor.getText() + "\n");
+
+    let url = aEvent.detail.url;
+    if (url.indexOf("-02.js") != -1) {
+      window.removeEventListener(aEvent.type, _onEvent);
+
+      executeSoon(function() {
+        info("Editor caret position: " + gEditor.getCaretPosition().toSource() + "\n");
+        ok(gEditor.getCaretPosition().line == 5 &&
+           gEditor.getCaretPosition().col == 8 + token.length,
+          "The editor didn't jump to the correct line. (3)");
+        is(gScripts.visibleItemsCount, 1,
+          "Not all the correct scripts are shown after the search. (3)");
+
         finalCheck(0, "ugger;", token);
       });
     }
@@ -115,7 +160,7 @@ function finalCheck(i, string, token) {
 
   ok(gEditor.getCaretPosition().line == 5 &&
      gEditor.getCaretPosition().col == 8 + token.length + i,
-    "The editor didn't remain at the correct token. (3)");
+    "The editor didn't remain at the correct token. (4)");
 
   if (string[i]) {
     EventUtils.sendChar(string[i]);
@@ -126,7 +171,7 @@ function finalCheck(i, string, token) {
   clear();
   ok(gEditor.getCaretPosition().line == 5 &&
      gEditor.getCaretPosition().col == 8 + token.length + i,
-    "The editor didn't remain at the correct token. (4)");
+    "The editor didn't remain at the correct token. (5)");
 
   executeSoon(function() {
     let noMatchingScripts = gDebugger.L10N.getStr("noMatchingScriptsText");
@@ -139,7 +184,7 @@ function finalCheck(i, string, token) {
     write("BOGUS");
     ok(gEditor.getCaretPosition().line == 5 &&
        gEditor.getCaretPosition().col == 8 + token.length + i,
-      "The editor didn't remain at the correct token. (5)");
+      "The editor didn't remain at the correct token. (6)");
 
     is(gMenulist.getAttribute("label"), noMatchingScripts,
       "The menulist should display a notice that no scripts match the searched token.");
@@ -151,7 +196,7 @@ function finalCheck(i, string, token) {
     clear();
     ok(gEditor.getCaretPosition().line == 5 &&
        gEditor.getCaretPosition().col == 8 + token.length + i,
-      "The editor didn't remain at the correct token. (6)");
+      "The editor didn't remain at the correct token. (7)");
 
     isnot(gMenulist.getAttribute("label"), noMatchingScripts,
       "The menulist should not display a notice after the searchbox was emptied.");
@@ -171,6 +216,11 @@ function clear() {
 
 function write(text) {
   clear();
+  append(text);
+}
+
+function append(text) {
+  gSearchBox.focus();
 
   for (let i = 0; i < text.length; i++) {
     EventUtils.sendChar(text[i]);

browser/devtools/shared/DeveloperToolbar.jsm

@@ -550,7 +550,7 @@ function OutputPanel(aChromeDoc, aInput, aLoadCallback)
   this._loadCallback = aLoadCallback;
 
   /*
-  <panel id="gcli-output"
+  <tooltip id="gcli-output"
          noautofocus="true"
          noautohide="true"
          class="gcli-panel">
@@ -558,13 +558,15 @@ function OutputPanel(aChromeDoc, aInput, aLoadCallback)
                  id="gcli-output-frame"
                  src="chrome://browser/content/devtools/gclioutput.xhtml"
                  flex="1"/>
-  </panel>
+  </tooltip>
   */
-  this._panel = aChromeDoc.createElement("panel");
+
+  // TODO: Switch back from tooltip to panel when metacity focus issue is fixed:
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=780102
+  this._panel = aChromeDoc.createElement("tooltip");
+
   this._panel.id = "gcli-output";
   this._panel.classList.add("gcli-panel");
-  this._panel.setAttribute("noautofocus", "true");
-  this._panel.setAttribute("noautohide", "true");
   this._toolbar.parentElement.insertBefore(this._panel, this._toolbar);
 
   this._frame = aChromeDoc.createElementNS(NS_XHTML, "iframe");
@@ -579,6 +581,10 @@ function OutputPanel(aChromeDoc, aInput, aLoadCallback)
   this._frame.addEventListener("load", this._onload, true);
 
   this.loaded = false;
+  this.canHide = false;
+
+  this._onpopuphiding = this._onpopuphiding.bind(this);
+  this._panel.addEventListener("popuphiding", this._onpopuphiding, true);
 }
 
 /**
@@ -606,6 +612,18 @@ OutputPanel.prototype._onload = function OP_onload()
   }
 };
 
+/**
+ * Prevent the popup from hiding if it is not permitted via this.canHide.
+ */
+OutputPanel.prototype._onpopuphiding = function OP_onpopuphiding(aEvent)
+{
+  // TODO: When we switch back from tooltip to panel we can remove this hack:
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=780102
+  if (!this.canHide) {
+    aEvent.preventDefault();
+  }
+};
+
 /**
  * Display the OutputPanel.
  */
@@ -618,6 +636,8 @@ OutputPanel.prototype.show = function OP_show()
     this._resize();
   }.bind(this), 0);
 
+  this.canHide = false;
+
   this._panel.openPopup(this._input, "before_start", 0, 0, false, false, null);
   this._resize();
 
@@ -677,6 +697,7 @@ OutputPanel.prototype.update = function OP_update()
  */
 OutputPanel.prototype.remove = function OP_remove()
 {
+  this.canHide = true;
   this._panel.hidePopup();
 
   if (this.displayedOutput) {
@@ -693,11 +714,15 @@ OutputPanel.prototype.destroy = function OP_destroy()
 {
   this.remove();
 
+  this._panel.removeEventListener("popuphiding", this._onpopuphiding, true);
+
   this._panel.removeChild(this._frame);
   this._toolbar.parentElement.removeChild(this._panel);
 
   delete this._input;
   delete this._toolbar;
+  delete this._onload;
+  delete this._onpopuphiding;
   delete this._panel;
   delete this._frame;
   delete this._content;
@@ -714,6 +739,7 @@ OutputPanel.prototype._visibilityChanged = function OP_visibilityChanged(aEvent)
   if (aEvent.outputVisible === true) {
     // this.show is called by _outputChanged
   } else {
+    this.canHide = true;
     this._panel.hidePopup();
   }
 };
@@ -734,7 +760,7 @@ function TooltipPanel(aChromeDoc, aInput, aLoadCallback)
   this._onload = this._onload.bind(this);
   this._loadCallback = aLoadCallback;
   /*
-  <panel id="gcli-tooltip"
+  <tooltip id="gcli-tooltip"
          type="arrow"
          noautofocus="true"
          noautohide="true"
@@ -743,13 +769,15 @@ function TooltipPanel(aChromeDoc, aInput, aLoadCallback)
                  id="gcli-tooltip-frame"
                  src="chrome://browser/content/devtools/gclitooltip.xhtml"
                  flex="1"/>
-  </panel>
+  </tooltip>
   */
-  this._panel = aChromeDoc.createElement("panel");
+
+  // TODO: Switch back from tooltip to panel when metacity focus issue is fixed:
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=780102
+  this._panel = aChromeDoc.createElement("tooltip");
+
   this._panel.id = "gcli-tooltip";
   this._panel.classList.add("gcli-panel");
-  this._panel.setAttribute("noautofocus", "true");
-  this._panel.setAttribute("noautohide", "true");
   this._toolbar.parentElement.insertBefore(this._panel, this._toolbar);
 
   this._frame = aChromeDoc.createElementNS(NS_XHTML, "iframe");
@@ -759,7 +787,12 @@ function TooltipPanel(aChromeDoc, aInput, aLoadCallback)
   this._panel.appendChild(this._frame);
 
   this._frame.addEventListener("load", this._onload, true);
+
   this.loaded = false;
+  this.canHide = false;
+
+  this._onpopuphiding = this._onpopuphiding.bind(this);
+  this._panel.addEventListener("popuphiding", this._onpopuphiding, true);
 }
 
 /**
@@ -785,6 +818,18 @@ TooltipPanel.prototype._onload = function TP_onload()
   }
 };
 
+/**
+ * Prevent the popup from hiding if it is not permitted via this.canHide.
+ */
+TooltipPanel.prototype._onpopuphiding = function TP_onpopuphiding(aEvent)
+{
+  // TODO: When we switch back from tooltip to panel we can remove this hack:
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=780102
+  if (!this.canHide) {
+    aEvent.preventDefault();
+  }
+};
+
 /**
  * Display the TooltipPanel.
  */
@@ -802,6 +847,8 @@ TooltipPanel.prototype.show = function TP_show(aDimensions)
     this._resize();
   }.bind(this), 0);
 
+  this.canHide = false;
+
   this._resize();
   this._panel.openPopup(this._input, "before_start", aDimensions.start * 10, 0, false, false, null);
   this._input.focus();
@@ -845,6 +892,7 @@ TooltipPanel.prototype._resize = function TP_resize()
  */
 TooltipPanel.prototype.remove = function TP_remove()
 {
+  this.canHide = true;
   this._panel.hidePopup();
 };
 
@@ -855,6 +903,8 @@ TooltipPanel.prototype.destroy = function TP_destroy()
 {
   this.remove();
 
+  this._panel.removeEventListener("popuphiding", this._onpopuphiding, true);
+
   this._panel.removeChild(this._frame);
   this._toolbar.parentElement.removeChild(this._panel);
 
@@ -862,6 +912,7 @@ TooltipPanel.prototype.destroy = function TP_destroy()
   delete this._dimensions;
   delete this._input;
   delete this._onload;
+  delete this._onpopuphiding;
   delete this._panel;
   delete this._frame;
   delete this._toolbar;
@@ -879,6 +930,7 @@ TooltipPanel.prototype._visibilityChanged = function TP_visibilityChanged(aEvent
   if (aEvent.tooltipVisible === true) {
     this.show(aEvent.dimensions);
   } else {
+    this.canHide = true;
     this._panel.hidePopup();
   }
 };

toolkit/devtools/debugger/server/dbg-script-actors.js

@@ -25,10 +25,15 @@ function ThreadActor(aHooks)
   this._frameActors = [];
   this._environmentActors = [];
   this._hooks = aHooks ? aHooks : {};
-  this._breakpointStore = {};
   this._scripts = {};
 }
 
+/**
+ * The breakpoint store must be shared across instances of ThreadActor so that
+ * page reloads don't blow away all of our breakpoints.
+ */
+ThreadActor._breakpointStore = {};
+
 ThreadActor.prototype = {
   actorPrefix: "context",
 
@@ -36,6 +41,8 @@ ThreadActor.prototype = {
 
   get dbg() { return this._dbg; },
 
+  get _breakpointStore() { return ThreadActor._breakpointStore; },
+
   get threadLifetimePool() {
     if (!this._threadLifetimePool) {
       this._threadLifetimePool = new ActorPool(this.conn);

toolkit/devtools/debugger/tests/unit/test_breakpointstore.js

@@ -0,0 +1,19 @@
+/* -*- Mode: js; js-indent-level: 2; -*- */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Note: Removing this test will regress bug 754251. See comment above
+// ThreadActor._breakpointStore.
+
+function run_test()
+{
+  let loader = Cc["@mozilla.org/moz/jssubscript-loader;1"]
+    .getService(Components.interfaces.mozIJSSubScriptLoader);
+  loader.loadSubScript("chrome://global/content/devtools/dbg-script-actors.js");
+
+  let instance1 = new ThreadActor();
+  let instance2 = new ThreadActor();
+  do_check_eq(instance1._breakpointStore, ThreadActor._breakpointStore);
+  do_check_eq(instance2._breakpointStore, ThreadActor._breakpointStore);
+  do_check_eq(instance1._breakpointStore, instance2._breakpointStore);
+}

toolkit/devtools/debugger/tests/unit/xpcshell.ini

@@ -60,3 +60,4 @@ tail =
 [test_framebindings-05.js]
 [test_pause_exceptions-01.js]
 [test_pause_exceptions-02.js]
+[test_breakpointstore.js]