Fix ReadPixels implementation specific read format/type on desktop GL.

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 51 matching lines @@
     kGreen = 0x2,
     kBlue = 0x4,
     kAlpha = 0x8,
     kDepth = 0x10000,
     kStencil = 0x20000,
 
     kRGB = kRed | kGreen | kBlue,
     kRGBA = kRGB | kAlpha
   };
 
+  enum TargetESVersion {
+    kES2,
+    kES3
+  };
+
   struct EnumToString {
     uint32_t value;
     const char* name;
   };
 
   GLES2Util()
       : num_compressed_texture_formats_(0),
         num_shader_binary_formats_(0) {
   }
 
@@ skipping 48 matching lines @@
   static size_t GetGLTypeSizeForPathCoordType(uint32_t type);
 
   static uint32_t GLErrorToErrorBit(uint32_t gl_error);
 
   static uint32_t GLErrorBitToGLError(uint32_t error_bit);
 
   static uint32_t IndexToGLFaceTarget(int index);
 
   static size_t GLTargetToFaceIndex(uint32_t target);
 
-  static uint32_t GetPreferredGLReadPixelsFormat(uint32_t internal_format);
+  static uint32_t GetGLReadPixelsImplementationFormat(
+      uint32_t internal_format, TargetESVersion target_es_version);
 
-  static uint32_t GetPreferredGLReadPixelsType(
-      uint32_t internal_format, uint32_t texture_type);
+  static uint32_t GetGLReadPixelsImplementationType(
+      uint32_t internal_format, uint32_t texture_type,
+      TargetESVersion target_es_version);
 
   // Returns a bitmask for the channels the given format supports.
   // See ChannelBits.
   static uint32_t GetChannelsForFormat(int format);
 
   // Returns a bitmask for the channels the given attachment type needs.
   static uint32_t GetChannelsNeededForAttachmentType(
       int type, uint32_t max_color_attachments);
 
   // Return true if value is neither a power of two nor zero.
@@ skipping 70 matching lines @@
   bool lose_context_when_out_of_memory;
   // 0 if not a WebGL context.
   unsigned webgl_version;
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_