Pass initial size and GPU preference via context attributes

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h

 // Copyright (c) 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.
 
 // This file contains the GLES2DecoderPassthroughImpl class.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_
 
 #include "base/memory/ref_counted.h"
@@ skipping 23 matching lines @@
   Error DoCommands(unsigned int num_commands,
                    const void* buffer,
                    int num_entries,
                    int* entries_processed) override;
 
   const char* GetCommandName(unsigned int command_id) const override;
 
   bool Initialize(const scoped_refptr<gl::GLSurface>& surface,
                   const scoped_refptr<gl::GLContext>& context,
                   bool offscreen,
-                  const gfx::Size& offscreen_size,
                   const DisallowedFeatures& disallowed_features,
                   const ContextCreationAttribHelper& attrib_helper) override;
 
   // Destroys the graphics context.
   void Destroy(bool have_context) override;
 
   // Set the surface associated with the default FBO.
   void SetSurface(const scoped_refptr<gl::GLSurface>& surface) override;
 
   // Releases the surface associated with the GL context.
@@ skipping 193 matching lines @@
 
 // Include the prototypes of all the doer functions from a separate header to
 // keep this file clean.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doer_prototypes.h"
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_