cc: Partial tile update for one-copy raster.

cc/resources/resource_provider.h

 // Copyright 2012 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_RESOURCE_PROVIDER_H_
 #define CC_RESOURCES_RESOURCE_PROVIDER_H_
 
 #include <deque>
 #include <set>
 #include <string>
@@ skipping 315 matching lines @@
     ResourceProvider::Resource* resource_;
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager_;
     gfx::GpuMemoryBuffer* gpu_memory_buffer_;
     gfx::Size size_;
     ResourceFormat format_;
     base::ThreadChecker thread_checker_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedWriteLockGpuMemoryBuffer);
   };
 
+  class CC_EXPORT ScopedReadLockGpuMemoryBuffer {
+   public:
+    ScopedReadLockGpuMemoryBuffer(ResourceProvider* resource_provider,
+                                  ResourceProvider::ResourceId resource_id);
+    ~ScopedReadLockGpuMemoryBuffer();
+
+    gfx::GpuMemoryBuffer* GetGpuMemoryBuffer();
+
+   private:
+    ResourceProvider* resource_provider_;
+    ResourceProvider::ResourceId resource_id_;
+    gfx::GpuMemoryBuffer* gpu_memory_buffer_;
+    base::ThreadChecker thread_checker_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedReadLockGpuMemoryBuffer);
+  };
+
   class CC_EXPORT ScopedWriteLockGr {
    public:
     ScopedWriteLockGr(ResourceProvider* resource_provider,
                       ResourceProvider::ResourceId resource_id);
     ~ScopedWriteLockGr();
 
     void InitSkSurface(bool use_distance_field_text,
                        bool can_use_lcd_text,
                        int msaa_sample_count);
     void ReleaseSkSurface();
@@ skipping 313 matching lines @@
   return format_gl_data_format[format];
 }
 
 inline GLenum GLInternalFormat(ResourceFormat format) {
   return GLDataFormat(format);
 }
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_