Bug 1084979 - Prevent test_ipc.html from breaking subsequent tests that check for plugin/content crashes. r=jmaher

content/media/webspeech/synth/ipc/test/file_ipc.html

@@ -15,7 +15,12 @@
     window.is = parent.is;
     window.info = parent.info;
 
+    // The crash observer registration functions are stubbed out here to
+    // prevent the iframe test runner from breaking later crash-related tests.
     function iframeScriptFirst() {
+      SpecialPowers.prototype.registerProcessCrashObservers = () => {};
+      SpecialPowers.prototype.unregisterProcessCrashObservers = () => {};
+
       content.wrappedJSObject.RunSet.reloadAndRunAll({
           preventDefault: function() { },
           __exposedProps__: { preventDefault: 'r' }

dom/devicestorage/ipc/test_ipc.html

@@ -12,7 +12,12 @@
 
     SimpleTest.waitForExplicitFinish();
 
+    // The crash observer registration functions are stubbed out here to
+    // prevent the iframe test runner from breaking later crash-related tests.
     function iframeScriptFirst() {
+      SpecialPowers.prototype.registerProcessCrashObservers = () => {};
+      SpecialPowers.prototype.unregisterProcessCrashObservers = () => {};
+
       content.wrappedJSObject.RunSet.reloadAndRunAll({
           preventDefault: function() { },
           __exposedProps__: { preventDefault: 'r' }

dom/media/tests/ipc/test_ipc.html

@@ -18,10 +18,11 @@
     // killed.
     SimpleTest.requestLongerTimeout(100);
 
-    // Disable crash observers as it breaks later tests.
+    // The crash observer registration functions are stubbed out here to
+    // prevent the iframe test runner from breaking later crash-related tests.
     function iframeScriptFirst() {
-      SpecialPowers.prototype.registerProcessCrashObservers = function() { };
-      SpecialPowers.prototype.unregisterProcessCrashObservers = function() { };
+      SpecialPowers.prototype.registerProcessCrashObservers = () => {};
+      SpecialPowers.prototype.unregisterProcessCrashObservers = () => {};
 
       content.wrappedJSObject.RunSet.reloadAndRunAll({
         preventDefault: function() { },