Bug 897452 - Part 0.1 - Make it possible for TextureClient to call virtual methods just before its destructor. r=bjacob

gfx/layers/client/TextureClient.cpp

@@ -111,7 +111,8 @@ ShmemTextureClient::DropTextureData()
 }
 
 TextureClient::TextureClient(TextureFlags aFlags)
-  : mID(0)
+  : mRefCount(0)
+  , mID(0)
   , mFlags(aFlags)
   , mShared(false)
   , mValid(true)

gfx/layers/client/TextureClient.h

@@ -149,12 +149,28 @@ public:
  * In order to send several different buffers to the compositor side, use
  * several TextureClients.
  */
-class TextureClient : public AtomicRefCounted<TextureClient>
+class TextureClient
 {
 public:
   TextureClient(TextureFlags aFlags = TEXTURE_FLAGS_DEFAULT);
   virtual ~TextureClient();
 
+  void AddRef() {
+    MOZ_ASSERT(mRefCount >= 0);
+    ++mRefCount;
+  }
+
+  void Release() {
+    MOZ_ASSERT(mRefCount > 0);
+    if (0 == --mRefCount) {
+#ifdef DEBUG
+      mRefCount = detail::DEAD;
+#endif
+      Finalize();
+      delete this;
+    }
+  }
+
   virtual TextureClientSurface* AsTextureClientSurface() { return nullptr; }
   virtual TextureClientDrawTarget* AsTextureClientDrawTarget() { return nullptr; }
   virtual TextureClientYCbCr* AsTextureClientYCbCr() { return nullptr; }
@@ -253,6 +269,20 @@ public:
   // method to forget about the shmem _without_ releasing it.
   virtual void OnActorDestroy() {}
 
+private:
+  Atomic<int> mRefCount;
+
+  /**
+   * Called once, just before the destructor.
+   *
+   * Here goes the shut-down code that uses virtual methods.
+   * Must only be called by Release().
+   */
+  void Finalize()
+  {
+    // XXX Bug 897452 - Coming soon
+  }
+
 protected:
   void AddFlags(TextureFlags  aFlags)
   {