Allow creating GLImage-backed textures with glTexStorage2D.

gpu/command_buffer/tests/texture_image_factory.h

 // Copyright 2016 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.
 
 #include "gpu/command_buffer/service/image_factory.h"
 
 namespace gpu {
 
 // The images created by this factory have no inherent storage. When the image
 // is bound to a texture, storage is allocated for the texture via glTexImage2D.
 class TextureImageFactory : public gpu::ImageFactory {
  public:
   scoped_refptr<gl::GLImage> CreateImageForGpuMemoryBuffer(
       const gfx::GpuMemoryBufferHandle& handle,
       const gfx::Size& size,
       gfx::BufferFormat format,
       unsigned internalformat,
       int client_id,
       SurfaceHandle surface_handle) override;
   scoped_refptr<gl::GLImage> CreateAnonymousImage(
       const gfx::Size& size,
       gfx::BufferFormat format,
+      gfx::BufferUsage usage,
       unsigned internalformat) override;
   unsigned RequiredTextureType() override;
   bool SupportsFormatRGB() override;
 
   void SetRequiredTextureType(unsigned type);
 
  private:
   unsigned required_texture_type_ = 0;
 };
 
 }  // namespace gpu