Followup to bug 527876

dom/plugins/PluginInstanceChild.cpp

@@ -839,10 +839,9 @@ PluginInstanceChild::NPN_NewStream(NPMIMEType aMIMEType, const char* aWindow,
     return NPERR_NO_ERROR;
 }
 
-void
+bool
 PluginInstanceChild::InternalInvalidateRect(NPRect* aInvalidRect)
 {
-    // Should only be called on windowed plugins!
     NS_ASSERTION(aInvalidRect, "Null pointer!");
 
 #ifdef OS_WIN
@@ -851,4 +850,7 @@ PluginInstanceChild::InternalInvalidateRect(NPRect* aInvalidRect)
                   aInvalidRect->right, aInvalidRect->bottom };
     InvalidateRect(mPluginWindowHWND, &rect, FALSE);
 #endif
+
+    // Windowless plugins must return true!
+    return false;
 }

dom/plugins/PluginInstanceChild.h

@@ -165,7 +165,9 @@ public:
     NPN_NewStream(NPMIMEType aMIMEType, const char* aWindow,
                   NPStream** aStream);
 
-    void
+    // Return true if you want to send the notification to the parent process
+    // also.
+    bool
     InternalInvalidateRect(NPRect* aInvalidRect);
 
 private:

dom/plugins/PluginModuleChild.cpp

@@ -736,10 +736,11 @@ _invalidaterect(NPP aNPP,
     AssertPluginThread();
 
     PluginInstanceChild* actor = InstCast(aNPP);
-    actor->SendNPN_InvalidateRect(*aInvalidRect);
+    bool sendToParent = actor->InternalInvalidateRect(aInvalidRect);
 
-    // Some platforms need additional help to redraw in this process.
-    actor->InternalInvalidateRect(aInvalidRect);
+    if (sendToParent) {
+        actor->SendNPN_InvalidateRect(*aInvalidRect);
+    }
 }
 
 void NP_CALLBACK