cc: Lock resources directly in CALayerOverlay

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 327 matching lines @@
     ScopedReadLockGpuMemoryBuffer(ResourceProvider* resource_provider,
                                   ResourceId resource_id);
     ~ScopedReadLockGpuMemoryBuffer();
 
     // This may return nullptr.
     gfx::GpuMemoryBuffer* GetGpuMemoryBuffer() const;
 
     // This returns the GL texture that is backed by a GL image bound to the
     // resource's GpuMemoryBuffer.
     unsigned GetTextureId() const;
-
     ResourceId GetResourceId() const;
+    bool IsOverlayCandidate() const;

[erikchen, 2016/05/26 00:32:01]

not necessary if you choose to follow my suggestion.

 
    private:
     ResourceProvider* resource_provider_;
     ResourceId resource_id_;
     const ResourceProvider::Resource* resource_;
     base::ThreadChecker thread_checker_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedReadLockGpuMemoryBuffer);
   };
 
@@ skipping 340 matching lines @@
   // A process-unique ID used for disambiguating memory dumps from different
   // resource providers.
   int tracing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_