Reland of Select correct copy method for DoCopySubTexture

gpu/command_buffer/common/gles2_cmd_utils.h

 // Copyright (c) 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.
 
 // This file is here so other GLES2 related files can have a common set of
 // includes where appropriate.
 
 #ifndef GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_
 #define GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_
 
@@ skipping 225 matching lines @@
       uint64_t v64, uint32_t* v32_0, uint32_t* v32_1);
   static uint64_t MapTwoUint32ToUint64(uint32_t v32_0, uint32_t v32_1);
 
   static uint32_t MapBufferTargetToBindingEnum(uint32_t target);
 
   static bool IsUnsignedIntegerFormat(uint32_t internal_format);
   static bool IsSignedIntegerFormat(uint32_t internal_format);
   static bool IsIntegerFormat(uint32_t internal_format);
   static bool IsFloatFormat(uint32_t internal_format);
   static uint32_t ConvertToSizedFormat(uint32_t format, uint32_t type);
+  static bool IsSizedColorFormat(uint32_t internal_format);
 
-  static bool IsSizedColorFormat(uint32_t internal_format);
+  // Infer color encoding from internalformat
+  static int GetColorEncodingFromInternalFormat(uint32_t internalformat);
+
   static void GetColorFormatComponentSizes(
       uint32_t internal_format, uint32_t type, int* r, int* g, int* b, int* a);
 
   // Computes the data size for certain gl commands like glUniform.
   static bool ComputeDataSize(uint32_t count,
                               size_t size,
                               unsigned int elements_per_unit,
                               uint32_t* dst);
 
   #include "../common/gles2_cmd_utils_autogen.h"
@@ skipping 72 matching lines @@
   bool should_use_native_gmb_for_backbuffer;
 
   ContextType context_type;
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_