cc: Hide Gpu Rasterization details in Resource Provider.

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 301 matching lines @@
     virtual bool HasPassed() = 0;
 
    protected:
     friend class base::RefCounted<Fence>;
     virtual ~Fence() {}
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Fence);
   };
 
+  // This class is used to begin and end gpu rasterization.

[reveman, 2014/07/01 17:19:01]

How about something like this instead:

// The following class is needed to modify GL resources using GPU
// raster. The user must ensure that they only use GPU raster on
// GL resources while an instance of this class is alive.

provides some more details for how this is supposed to be used. It would also be
nice to enforce this using assertions but that might be outside the scope of
this patch.

[sohanjg, 2014/07/02 07:40:37]

Done.

+  class CC_EXPORT ScopedGpuRaster {
+   public:
+    ScopedGpuRaster(ResourceProvider* resource_provider, const char* name);
+    ~ScopedGpuRaster();
+
+   private:
+    void BeginGpuRaster(const char* name);
+    void EndGpuRaster();

[reveman, 2014/07/01 17:19:01]

How about keeping these as private ResourceProvider methods instead? I think
that would be a bit more consistent with ScopedSamplerGL and a bit more flexible
in case we need to use this differently in the future.

[sohanjg, 2014/07/02 07:40:37]

Done.

+    gpu::gles2::GLES2Interface* gl_;
+    class GrContext* gr_context_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedGpuRaster);
+  };

[reveman, 2014/07/01 17:19:01]

Please move this class above the Fence class so all Scoped* classes are grouped
together.

[sohanjg, 2014/07/02 07:40:37]

Done.

+
   // Returns a canvas for gpu rasterization.
   // Call Unmap before the resource can be read or used for compositing.
   // It is used for direct gpu rasterization.
   SkCanvas* MapGpuRasterBuffer(ResourceId id);
   void UnmapGpuRasterBuffer(ResourceId id);
 
   // Returns a canvas backed by an image buffer. UnmapImageRasterBuffer
   // returns true if canvas was written to while mapped.
   // Rasterizing to the canvas writes the content into the image buffer,
   // which is internally bound to the underlying resource when read.
@@ skipping 370 matching lines @@
   return format_gl_data_format[format];
 }
 
 inline GLenum GLInternalFormat(ResourceFormat format) {
   return GLDataFormat(format);
 }
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_