Bug 784378 - 'Apps API - Clear Private Data'. r=jlebar.

dom/apps/src/Webapps.js

@@ -12,6 +12,7 @@ Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/DOMRequestHelper.jsm");
 Cu.import("resource://gre/modules/ObjectWrapper.jsm");
 Cu.import("resource://gre/modules/AppsUtils.jsm");
+Cu.import("resource://gre/modules/BrowserElementPromptService.jsm");
 
 XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
                                    "@mozilla.org/childprocessmessagemanager;1",
@@ -319,6 +320,14 @@ WebappsApplication.prototype = {
     return request;
   },
 
+  clearBrowserData: function() {
+    let browserChild =
+      BrowserElementPromptService.getBrowserElementChildForWindow(this._window);
+    if (browserChild) {
+      browserChild.messageManager.sendAsyncMessage("Webapps:ClearBrowserData");
+    }
+  },
+
   uninit: function() {
     this._onprogress = null;
     cpmm.sendAsyncMessage("Webapps:UnregisterForMessages",

dom/apps/src/Webapps.jsm

@@ -63,6 +63,8 @@ let DOMApplicationRegistry = {
                      "Webapps:GetList", "Webapps:RegisterForMessages",
                      "Webapps:UnregisterForMessages"];
 
+    this.frameMessages = ["Webapps:ClearBrowserData"];
+
     this.messages.forEach((function(msgName) {
       ppmm.addMessageListener(msgName, this);
     }).bind(this));
@@ -1136,6 +1138,79 @@ let DOMApplicationRegistry = {
     return true;
 #endif
 
+  },
+
+  _notifyCategoryAndObservers: function(subject, topic, data) {
+    const serviceMarker = "service,";
+
+    // First create observers from the category manager.
+    let cm =
+      Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
+    let enumerator = cm.enumerateCategory(topic);
+
+    let observers = [];
+
+    while (enumerator.hasMoreElements()) {
+      let entry =
+        enumerator.getNext().QueryInterface(Ci.nsISupportsCString).data;
+      let contractID = cm.getCategoryEntry(topic, entry);
+
+      let factoryFunction;
+      if (contractID.substring(0, serviceMarker.length) == serviceMarker) {
+        contractID = contractID.substring(serviceMarker.length);
+        factoryFunction = "getService";
+      }
+      else {
+        factoryFunction = "createInstance";
+      }
+
+      try {
+        let handler = Cc[contractID][factoryFunction]();
+        if (handler) {
+          let observer = handler.QueryInterface(Ci.nsIObserver);
+          observers.push(observer);
+        }
+      } catch(e) { }
+    }
+
+    // Next enumerate the registered observers.
+    enumerator = Services.obs.enumerateObservers(topic);
+    while (enumerator.hasMoreElements()) {
+      let observer = enumerator.getNext();
+      if (observers.indexOf(observer) == -1) {
+        observers.push(observer);
+      }
+    }
+
+    observers.forEach(function (observer) {
+      try {
+        observer.observe(subject, topic, data);
+      } catch(e) { }
+    });
+  },
+
+  registerBrowserElementParentForApp: function(bep, appId) {
+    let mm = bep._mm;
+
+    // Make a listener function that holds on to this appId.
+    let listener = this.receiveAppMessage.bind(this, appId);
+
+    this.frameMessages.forEach(function(msgName) {
+      mm.addMessageListener(msgName, listener);
+    });
+  },
+
+  receiveAppMessage: function(appId, message) {
+    switch (message.name) {
+      case "Webapps:ClearBrowserData":
+        let subject = {
+          appId: appId,
+          browserOnly: true,
+          QueryInterface: XPCOMUtils.generateQI([Ci.mozIApplicationClearPrivateDataParams])
+        };
+        this._notifyCategoryAndObservers(subject, "webapps-clear-data", null);
+        break;
+    }
   }
 };
 

dom/browser-element/BrowserElementChild.js

@@ -675,6 +675,18 @@ BrowserElementChild.prototype = {
     onProgressChange: function(webProgress, request, curSelfProgress,
                                maxSelfProgress, curTotalProgress, maxTotalProgress) {},
   },
+
+  // Expose the message manager for WebApps and others.
+  _messageManagerPublic: {
+    sendAsyncMessage: global.sendAsyncMessage.bind(global),
+    sendSyncMessage: global.sendSyncMessage.bind(global),
+    addMessageListener: global.addMessageListener.bind(global),
+    removeMessageListener: global.removeMessageListener.bind(global)
+  },
+
+  get messageManager() {
+    return this._messageManagerPublic;
+  }
 };
 
 var api = new BrowserElementChild();

dom/browser-element/BrowserElementParent.js

@@ -13,6 +13,11 @@ Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/BrowserElementPromptService.jsm");
 
+XPCOMUtils.defineLazyGetter(this, "DOMApplicationRegistry", function () {
+  Cu.import("resource://gre/modules/Webapps.jsm");
+  return DOMApplicationRegistry;
+});
+
 const NS_PREFBRANCH_PREFCHANGE_TOPIC_ID = "nsPref:changed";
 const BROWSER_FRAMES_ENABLED_PREF = "dom.mozBrowserFramesEnabled";
 const TOUCH_EVENTS_ENABLED_PREF = "dom.w3c_touch_events.enabled";
@@ -250,6 +255,18 @@ function BrowserElementParent(frameLoader, hasRemoteFrame) {
 
   // Insert ourself into the prompt service.
   BrowserElementPromptService.mapFrameToBrowserElementParent(this._frameElement, this);
+
+  // If this browser represents an app then let the Webapps module register for
+  // any messages that it needs.
+  let appManifestURL =
+    this._frameElement.QueryInterface(Ci.nsIMozBrowserFrame).appManifestURL;
+  if (appManifestURL) {
+    let appId =
+      DOMApplicationRegistry.getAppLocalIdByManifestURL(appManifestURL);
+    if (appId != Ci.nsIScriptSecurityManager.NO_APP_ID) {
+      DOMApplicationRegistry.registerBrowserElementParentForApp(this, appId);
+    }
+  }
 }
 
 BrowserElementParent.prototype = {

dom/interfaces/apps/Makefile.in

@@ -16,6 +16,7 @@ GRE_MODULE     = 1
 
 XPIDLSRCS =                               \
             mozIApplication.idl \
+            mozIApplicationClearPrivateDataParams.idl \
             nsIDOMApplicationRegistry.idl \
             nsIDOMApplicationRegistry2.idl \
             nsIAppsService.idl \

dom/interfaces/apps/nsIDOMApplicationRegistry.idl

@@ -8,7 +8,7 @@
 interface nsIDOMDOMRequest;
 interface nsIArray;
 
-[scriptable, uuid(e3649c1d-c950-495e-b0ed-6ce40be9743b)]
+[scriptable, uuid(738360f5-19ad-456a-a477-cdbc250e1718)]
 interface mozIDOMApplication  : nsISupports
 {
   readonly attribute jsval manifest;
@@ -41,6 +41,9 @@ interface mozIDOMApplication  : nsISupports
   /* startPoint will be used when several launch_path exists for an app */
   nsIDOMDOMRequest launch([optional] in DOMString startPoint);
   nsIDOMDOMRequest uninstall();
+
+  /* Clear data that has been collected through mozbrowser elements. */
+  void clearBrowserData();
 };
 
 [scriptable, uuid(4c36ca48-841e-4d5a-8c46-dda14ac633ca)]