Mac: Always use surfaceless mode

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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 "content/browser/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 48 matching lines @@
 #include "content/browser/compositor/software_output_device_ozone.h"
 #include "ui/ozone/public/overlay_candidates_ozone.h"
 #include "ui/ozone/public/overlay_manager_ozone.h"
 #include "ui/ozone/public/ozone_platform.h"
 #include "ui/ozone/public/ozone_switches.h"
 #elif defined(USE_X11)
 #include "content/browser/compositor/software_output_device_x11.h"
 #elif defined(OS_MACOSX)
 #include "content/browser/compositor/browser_compositor_overlay_candidate_validator_mac.h"
 #include "content/browser/compositor/software_output_device_mac.h"
+#include "ui/base/cocoa/remote_layer_api.h"
 #endif
 
 using cc::ContextProvider;
 using gpu::gles2::GLES2Interface;
 
 static const int kNumRetriesBeforeSoftwareFallback = 4;
 
 namespace content {
 namespace {
 
@@ skipping 90 matching lines @@
           ->CreateOverlayCandidates(widget);
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (overlay_candidates &&
       (command_line->HasSwitch(switches::kEnableHardwareOverlays) ||
        command_line->HasSwitch(switches::kOzoneTestSingleOverlaySupport))) {
     return scoped_ptr<BrowserCompositorOverlayCandidateValidator>(
         new BrowserCompositorOverlayCandidateValidatorOzone(
             widget, overlay_candidates.Pass()));
   }
 #elif defined(OS_MACOSX)
-  return make_scoped_ptr(
-      new BrowserCompositorOverlayCandidateValidatorMac(widget));
+  // Overlays are only supported through the remote layer API.
+  if (ui::RemoteLayerAPISupported()) {
+    return make_scoped_ptr(
+        new BrowserCompositorOverlayCandidateValidatorMac(widget));
+  }
 #endif
   return scoped_ptr<BrowserCompositorOverlayCandidateValidator>();
 }
 
 static bool ShouldCreateGpuOutputSurface(ui::Compositor* compositor) {
 #if defined(OS_CHROMEOS)
   // Software fallback does not happen on Chrome OS.
   return true;
 #endif
 
@@ skipping 449 matching lines @@
   FOR_EACH_OBSERVER(ImageTransportFactoryObserver,
                     observer_list_,
                     OnLostResources());
 
   // Kill things that use the shared context before killing the shared context.
   lost_gl_helper.reset();
   lost_shared_main_thread_contexts  = NULL;
 }
 
 }  // namespace content