cc: Move RasterBuffer implementations from ResourceProvider to RasterWorkerPool implementations.

cc/resources/raster_buffer.h

 // Copyright 2014 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_RASTER_BUFFER_H_
 #define CC_RESOURCES_RASTER_BUFFER_H_
 
+#include "cc/base/cc_export.h"
 #include "skia/ext/refptr.h"
 
 class SkCanvas;
 
 namespace cc {
 
-class RasterBuffer {
+class CC_EXPORT RasterBuffer {
  public:
+  RasterBuffer();
+  virtual ~RasterBuffer();
+
   virtual skia::RefPtr<SkCanvas> AcquireSkCanvas() = 0;
   virtual void ReleaseSkCanvas(const skia::RefPtr<SkCanvas>& canvas) = 0;
-
- protected:
-  virtual ~RasterBuffer() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RASTER_BUFFER_H_