This change adds the apple software renderer as an option on Chrome/Mac. It's enabled by passing...

ui/gfx/gl/gl_implementation.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_GFX_GL_GL_IMPLEMENTATION_H_
 #define UI_GFX_GL_GL_IMPLEMENTATION_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/native_library.h"
 #include "build/build_config.h"
 #include "ui/gfx/gl/gl_export.h"
 #include "ui/gfx/gl/gl_switches.h"
 
 namespace gfx {
 
 class GLContext;
 
 // The GL implementation currently in use.
 enum GLImplementation {
   kGLImplementationNone,
   kGLImplementationDesktopGL,
   kGLImplementationOSMesaGL,
+  kGLImplementationAppleGL,
   kGLImplementationEGLGLES2,
   kGLImplementationMockGL
 };
 
 void GetAllowedGLImplementations(std::vector<GLImplementation>* impls);
 
 #if defined(OS_WIN)
 typedef void* (WINAPI *GLGetProcAddressProc)(const char* name);
 #else
 typedef void* (*GLGetProcAddressProc)(const char* name);
@@ skipping 40 matching lines @@
 // EGL based implementations core entry points will not be queried through
 // GLGetProcAddressProc.
 void* GetGLCoreProcAddress(const char* name);
 
 // Find an entry point in the current GL implementation.
 void* GetGLProcAddress(const char* name);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GL_GL_IMPLEMENTATION_H_