Always use webkit compositor

ui/gfx/compositor/compositor_cc.cc

 // 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.
 
 #include "ui/gfx/compositor/compositor_cc.h"
 
 #include "base/command_line.h"
 #include "third_party/skia/include/images/SkImageEncoder.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCompositor.h"
@@ skipping 246 matching lines @@
 
 void CompositorCC::applyScrollDelta(const WebKit::WebSize&) {
 }
 
 WebKit::WebGraphicsContext3D* CompositorCC::createContext3D() {
   WebKit::WebGraphicsContext3D* context;
   if (test_compositor_enabled) {
     // Use context that results in no rendering to the screen.
     context = new TestWebGraphicsContext3D();
   } else {
+#if defined(OS_MACOSX) && !defined(USE_AURA)
+    // Non-Aura builds compile this code but doesn't call it. Unfortunately
+    // this is where we translate gfx::AcceleratedWidget to
+    // gfx::PluginWindowHandle, and they are different on non-Aura Mac.
+    // TODO(piman): remove ifdefs when AcceleratedWidget is rationalized on Mac.
+    NOTIMPLEMENTED();
+    return NULL;
+#else
     gfx::GLShareGroup* share_group =
         SharedResourcesCC::GetInstance()->GetShareGroup();
     context = new webkit::gpu::WebGraphicsContext3DInProcessImpl(
         widget_, share_group);
+#endif
   }
   WebKit::WebGraphicsContext3D::Attributes attrs;
   context->initialize(attrs, 0, true);
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (!command_line->HasSwitch(switches::kDisableUIVsync)) {
     context->makeContextCurrent();
     gfx::GLContext* gl_context = gfx::GLContext::GetCurrent();
     gl_context->SetSwapInterval(1);
     gl_context->ReleaseCurrent(NULL);
@@ skipping 24 matching lines @@
       switches::kDisableTestCompositor)) {
     test_compositor_enabled = true;
   }
 }
 
 COMPOSITOR_EXPORT void DisableTestCompositor() {
   test_compositor_enabled = false;
 }
 
 }  // namespace ui