Bug 1130971 - Null pointer checks before dispatching. r=mattwoodrow

--HG--
extra : rebase_source : f38f8831801730d4e9faf5701ad6210717a2fbc4

gfx/layers/ipc/ImageBridgeChild.cpp

@@ -364,6 +364,10 @@ static void ReleaseImageClientNow(ImageClient* aClient)
 // static
 void ImageBridgeChild::DispatchReleaseImageClient(ImageClient* aClient)
 {
+  if (!aClient) {
+    return;
+  }
+
   if (!IsCreated()) {
     // CompositableClient::Release should normally happen in the ImageBridgeChild
     // thread because it usually generate some IPDL messages.
@@ -423,7 +427,7 @@ static void UpdateImageClientNow(ImageClient* aClient, ImageContainer* aContaine
 void ImageBridgeChild::DispatchImageClientUpdate(ImageClient* aClient,
                                                  ImageContainer* aContainer)
 {
-  if (!IsCreated()) {
+  if (!aClient || !aContainer || !IsCreated()) {
     return;
   }