Add a new ozone switch to enable surfaceless output 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 207 matching lines @@
     scoped_ptr<SoftwareBrowserCompositorOutputSurface> surface(
         new SoftwareBrowserCompositorOutputSurface(
             output_surface_proxy_,
             CreateSoftwareOutputDevice(compositor),
             per_compositor_data_[compositor]->surface_id,
             &output_surface_map_,
             compositor->vsync_manager()));
     return surface.PassAs<cc::OutputSurface>();
   }
 
-  scoped_ptr<BrowserCompositorOutputSurface> surface(
-      new GpuBrowserCompositorOutputSurface(
-          context_provider,
-          per_compositor_data_[compositor]->surface_id,
-          &output_surface_map_,
-          compositor->vsync_manager(),
-          CreateOverlayCandidateValidator(compositor->widget())));
+  scoped_ptr<BrowserCompositorOutputSurface> surface;
+#if defined(USE_OZONE)
+  if (ui::SurfaceFactoryOzone::GetInstance()->CanShowPrimaryPlaneAsOverlay()) {
+    NOTIMPLEMENTED();
+    return scoped_ptr<cc::OutputSurface>();  // TODO(achaulk) implementation.

[danakj, 2014/08/08 15:41:20]

What's the point of adding this in this CL if it clearly doesn't work?

[achaulk, 2014/08/08 15:46:03]

It was mostly to show where/how it would be used, but I could delay this bit
until the next CL

[danakj, 2014/08/08 15:46:48]

Ya, I think it would make sense to add it once it does something.

[achaulk, 2014/08/08 15:49:21]

Done.

+  }
+#endif
+  if (!surface)

[danakj, 2014/08/08 15:46:48]

(btw you'd need {} for this cuz multi-line body.)

+    surface.reset(new GpuBrowserCompositorOutputSurface(
+        context_provider,
+        per_compositor_data_[compositor]->surface_id,
+        &output_surface_map_,
+        compositor->vsync_manager(),
+        CreateOverlayCandidateValidator(compositor->widget())));
+
   if (data->reflector.get())
     data->reflector->ReattachToOutputSurfaceFromMainThread(surface.get());
 
   return surface.PassAs<cc::OutputSurface>();
 }
 
 scoped_refptr<ui::Reflector> GpuProcessTransportFactory::CreateReflector(
     ui::Compositor* source,
     ui::Layer* target) {
   PerCompositorData* data = per_compositor_data_[source];
@@ skipping 208 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