Bug 722428: Sprinkle weakref pixie dust on SpecialPowers to avoid leaks until shutdown. r=ctalbert

testing/mochitest/specialpowers/content/specialpowers.js

@@ -39,7 +39,7 @@
  */
 
 function SpecialPowers(window) {
-  this.window = window;
+  this.window = Components.utils.getWeakReference(window);
   this._encounteredCrashDumpFiles = [];
   this._unexpectedCrashDumpFiles = { };
   this._crashDumpDir = null;

testing/mochitest/tests/SimpleTest/specialpowersAPI.js

@@ -63,6 +63,7 @@ function bindDOMWindowUtils(aWindow) {
 
   var util = aWindow.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                    .getInterface(Components.interfaces.nsIDOMWindowUtils);
+  var weakUtil = Components.utils.getWeakReference(util);
   // This bit of magic brought to you by the letters
   // B Z, and E, S and the number 5.
   //
@@ -77,7 +78,10 @@ function bindDOMWindowUtils(aWindow) {
     if (prop in desc && typeof(desc[prop]) == "function") {
       var oldval = desc[prop];
       try {
-        desc[prop] = function() { return oldval.apply(util, arguments); };
+        desc[prop] = function() {
+          utils = weakUtil.get();
+          return oldval.apply(utils, arguments);
+        };
       } catch (ex) {
         dump("WARNING: Special Powers failed to rebind function: " + desc + "::" + prop + "\n");
       }
@@ -426,7 +430,7 @@ SpecialPowersAPI.prototype = {
   },
 
   getDOMWindowUtils: function(aWindow) {
-    if (aWindow == this.window && this.DOMWindowUtils != null)
+    if (aWindow == this.window.get() && this.DOMWindowUtils != null)
       return this.DOMWindowUtils;
 
     return bindDOMWindowUtils(aWindow);
@@ -814,7 +818,7 @@ SpecialPowersAPI.prototype = {
   },
 
   snapshotWindow: function (win, withCaret) {
-    var el = this.window.document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
+    var el = this.window.get().document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
     el.width = win.innerWidth;
     el.height = win.innerHeight;
     var ctx = el.getContext("2d");
@@ -1029,7 +1033,7 @@ SpecialPowersAPI.prototype = {
   },
 
   snapshotWindow: function (win, withCaret) {
-    var el = this.window.document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
+    var el = this.window.get().document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
     el.width = win.innerWidth;
     el.height = win.innerHeight;
     var ctx = el.getContext("2d");