Add shared bitmap managers for browser and renderer processes.

cc/resources/shared_bitmap.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_RESOURCES_SHARED_BITMAP_H_
 #define CC_RESOURCES_SHARED_BITMAP_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/shared_memory.h"
 #include "cc/base/cc_export.h"
 #include "gpu/command_buffer/common/mailbox.h"
+#include "ui/gfx/size.h"
 
 namespace base { class SharedMemory; }
 
 namespace cc {
 typedef gpu::Mailbox SharedBitmapId;
 
 class CC_EXPORT SharedBitmap {
  public:
   SharedBitmap(base::SharedMemory* memory,
                const SharedBitmapId& id,
                const base::Callback<void(SharedBitmap*)>& free_callback);
 
   ~SharedBitmap();
 
   bool operator<(const SharedBitmap& right) const {
     if (memory_ < right.memory_)
       return true;
     if (memory_ > right.memory_)
       return false;
     return id_ < right.id_;
   }
 
   uint8* pixels() { return static_cast<uint8*>(memory_->memory()); }
 
   base::SharedMemory* memory() { return memory_; }
 
   SharedBitmapId id() { return id_; }
 
+  // Returns true if the size is valid and false otherwise.
+  static bool GetSizeInBytes(const gfx::Size& size, size_t* size_in_bytes);
+
+  static SharedBitmapId GenerateId();
+
  private:
   base::SharedMemory* memory_;
   SharedBitmapId id_;
   base::Callback<void(SharedBitmap*)> free_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SharedBitmap);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_SHARED_BITMAP_H_