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

ui/gfx/gl/gl_context_mac.mm

 // 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.
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/memory/scoped_generic_obj.h"
 #include "base/memory/scoped_ptr.h"
 #include "third_party/mesa/MesaLib/include/GL/osmesa.h"
@@ skipping 22 matching lines @@
 
 namespace gfx {
 
 class GLShareGroup;
 
 scoped_refptr<GLContext> GLContext::CreateGLContext(
     GLShareGroup* share_group,
     GLSurface* compatible_surface,
     GpuPreference gpu_preference) {
   switch (GetGLImplementation()) {
-    case kGLImplementationDesktopGL: {
+    case kGLImplementationDesktopGL:
+    case kGLImplementationAppleGL: {
       scoped_refptr<GLContext> context;
 #if defined(USE_AURA)
       if (compatible_surface->IsOffscreen())
         context = new GLContextCGL(share_group);
       else
         context = new GLContextNSView(share_group);
 #else
       context = new GLContextCGL(share_group);
 #endif // USE_AURA
       if (!context->Initialize(compatible_surface, gpu_preference))
@@ skipping 91 matching lines @@
   }
 
   if (found_online && found_offline) {
     supports_dual_gpus = true;
   }
 
   return supports_dual_gpus;
 }
 
 }  // namespace gfx