Bug 1333892 - Remove unused IPC message leftover from B2G days. r=kanru

MozReview-Commit-ID: 2qBq6WjzbcO

dom/ipc/TabChild.cpp

@@ -2732,11 +2732,7 @@ TabChild::MakeHidden()
     return;
   }
 
-  CompositorBridgeChild* compositor = CompositorBridgeChild::Get();
-
-  // Clear cached resources directly. This avoids one extra IPC
-  // round-trip from CompositorBridgeChild to CompositorBridgeParent.
-  compositor->RecvClearCachedResources(mLayersId);
+  ClearCachedResources();
 
   // Hide all plugins in this tab.
   if (nsCOMPtr<nsIPresShell> shell = GetPresShell()) {

gfx/layers/ipc/CompositorBridgeChild.cpp

@@ -585,16 +585,6 @@ CompositorBridgeChild::RecvDidComposite(const uint64_t& aId, const uint64_t& aTr
   return IPC_OK();
 }
 
-mozilla::ipc::IPCResult
-CompositorBridgeChild::RecvClearCachedResources(const uint64_t& aId)
-{
-  dom::TabChild* child = dom::TabChild::GetFrom(aId);
-  if (child) {
-    child->ClearCachedResources();
-  }
-  return IPC_OK();
-}
-
 void
 CompositorBridgeChild::ActorDestroy(ActorDestroyReason aWhy)
 {

gfx/layers/ipc/CompositorBridgeChild.h

@@ -93,9 +93,6 @@ public:
   // process). This may only be called on the main thread.
   static bool CompositorIsInGPUProcess();
 
-  virtual mozilla::ipc::IPCResult
-  RecvClearCachedResources(const uint64_t& id) override;
-
   virtual mozilla::ipc::IPCResult
   RecvDidComposite(const uint64_t& aId, const uint64_t& aTransactionId,
                    const TimeStamp& aCompositeStart,

gfx/layers/ipc/PCompositorBridge.ipdl

@@ -126,12 +126,6 @@ child:
    */
   async HideAllPlugins(uintptr_t aParentWidget);
 
-  /**
-   * Drop any buffers that might be retained on the child compositor
-   * side.
-   */
-  async ClearCachedResources(uint64_t id);
-
   async ParentAsyncMessages(AsyncParentMessageData[] aMessages);
 
   async ObserveLayerUpdate(uint64_t aLayersId, uint64_t aEpoch, bool aActive);