[Command Buffer] emulate SRGB color format for BlitFramebuffer in OpenGL

gpu/command_buffer/service/gles2_cmd_copy_tex_image.cc

 // 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.
 
 #include "gpu/command_buffer/service/gles2_cmd_copy_tex_image.h"
 
 #include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_version_info.h"
 
 namespace {
@@ skipping 23 matching lines @@
 CopyTexImageResourceManager::~CopyTexImageResourceManager() {}
 
 void CopyTexImageResourceManager::Initialize(
     const gles2::GLES2Decoder* decoder) {
   if (initialized_) {
     return;
   }
 
   blit_program_ = glCreateProgram();
 
-  // Compile the fragment shader
+  // Compile the vertex shader
   const char* vs_source =
       "#version 150\n"
       "out vec2 v_texcoord;\n"
       "\n"
       "void main()\n"
       "{\n"
       "    const vec2 quad_positions[6] = vec2[6]\n"
       "    (\n"
       "        vec2(0.0f, 0.0f),\n"
       "        vec2(0.0f, 1.0f),\n"
       "        vec2(1.0f, 0.0f),\n"
       "\n"
       "        vec2(0.0f, 1.0f),\n"
       "        vec2(1.0f, 0.0f),\n"
       "        vec2(1.0f, 1.0f)\n"
       "    );\n"
       "\n"
       "    gl_Position = vec4((quad_positions[gl_VertexID] * 2.0) - 1.0, 0.0, "
       "1.0);\n"
       "    v_texcoord = quad_positions[gl_VertexID];\n"
       "}\n";
 
   GLuint vs = glCreateShader(GL_VERTEX_SHADER);
   CompileShader(vs, vs_source);
   glAttachShader(blit_program_, vs);
   glDeleteShader(vs);
 
-  // Compile the vertex shader
+  // Compile the fragment shader
   const char* fs_source =
       "#version 150\n"
       "uniform sampler2D u_source_texture;\n"
       "in vec2 v_texcoord;\n"
       "out vec4 output_color;\n"
       "\n"
       "void main()\n"
       "{\n"
       "    output_color = texture(u_source_texture, v_texcoord);\n"
       "}\n";
@@ skipping 189 matching lines @@
       case GL_LUMINANCE_ALPHA:
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu