Remove PLATFORM(BLACKBERRY) support.

Source/WebCore/platform/graphics/PlatformLayer.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
 namespace WebCore {
 class TextureMapperPlatformLayer;
 typedef TextureMapperPlatformLayer PlatformLayer;
 };
 #elif USE(CLUTTER)
 typedef struct _ClutterActor ClutterActor;
 namespace WebCore {
 typedef ClutterActor PlatformLayer;
 };
 #endif
-#elif PLATFORM(BLACKBERRY)
-namespace WebCore {
-class LayerWebKitThread;
-typedef LayerWebKitThread PlatformLayer;
-}
 #else
 typedef void* PlatformLayer;
 #endif
 
 #endif // USE(ACCELERATED_COMPOSITING)
 
 #endif // PlatformLayer_h