Add PERSISTENT_MAP usage for GpuMemoryBuffers.

content/common/gpu/gpu_memory_buffer_factory.h

Index: content/common/gpu/gpu_memory_buffer_factory.h
diff --git a/content/common/gpu/gpu_memory_buffer_factory.h b/content/common/gpu/gpu_memory_buffer_factory.h
index 5eb0dfce1a93775074ca79fb72d16d38acee522a..99517218f011ca19a34a2c5c61e40e1982ab1394 100644
--- a/content/common/gpu/gpu_memory_buffer_factory.h
+++ b/content/common/gpu/gpu_memory_buffer_factory.h
@@ -35,7 +35,8 @@ class CONTENT_EXPORT GpuMemoryBufferFactory {
 
   // Gets system supported GPU memory buffer factory types. Preferred type at
   // the front of vector.
-  static void GetSupportedTypes(std::vector<gfx::GpuMemoryBufferType>* types);
+  static void GetSupportedTypes(gfx::GpuMemoryBuffer::Usage usage,
+                                std::vector<gfx::GpuMemoryBufferType>* types);

[reveman, 2015/05/19 16:12:12]

I'd rather not change this function. It might be removed in the near future and
the current idea is that it shouldn't take format or usage into account. Let me
know if using IsGpuMemoryBufferConfigurationSupported in GetImageTextureTarget
doesn't solve this problem.

 
   // Creates a new factory instance for |type|.
   static scoped_ptr<GpuMemoryBufferFactory> Create(