Remove SkBitmapHeap and SkBitmapHeapReader. They're unused.

src/core/SkValidatingReadBuffer.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkValidatingReadBuffer_DEFINED
 #define SkValidatingReadBuffer_DEFINED
 
 #include "SkRefCnt.h"
-#include "SkBitmapHeap.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkPath.h"
 #include "SkPicture.h"
 #include "SkReader32.h"
 
 class SkBitmap;
 
 class SkValidatingReadBuffer : public SkReadBuffer {
 public:
@@ skipping 56 matching lines @@
     static bool IsPtrAlign4(const void* ptr) {
         return SkIsAlign4((uintptr_t)ptr);
     }
 
     bool fError;
 
     typedef SkReadBuffer INHERITED;
 };
 
 #endif // SkValidatingReadBuffer_DEFINED