[ozone] Add an about flag to enable ozone overlay testing.

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 32 matching lines @@
 #include "ui/compositor/compositor_constants.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(OS_WIN)
 #include "content/browser/compositor/software_output_device_win.h"
 #elif defined(USE_OZONE)
 #include "content/browser/compositor/overlay_candidate_validator_ozone.h"
 #include "content/browser/compositor/software_output_device_ozone.h"
+#include "ui/ozone/public/ozone_switches.h"
 #include "ui/ozone/public/surface_factory_ozone.h"
 #elif defined(USE_X11)
 #include "content/browser/compositor/software_output_device_x11.h"
 #elif defined(OS_MACOSX)
 #include "content/browser/compositor/software_output_device_mac.h"
 #endif
 
 using cc::ContextProvider;
 using gpu::gles2::GLES2Interface;
 
@@ skipping 51 matching lines @@
   NOTREACHED();
   return scoped_ptr<cc::SoftwareOutputDevice>();
 #endif
 }
 
 scoped_ptr<cc::OverlayCandidateValidator> CreateOverlayCandidateValidator(
     gfx::AcceleratedWidget widget) {
 #if defined(USE_OZONE)
   ui::OverlayCandidatesOzone* overlay_candidates =
       ui::SurfaceFactoryOzone::GetInstance()->GetOverlayCandidates(widget);
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (overlay_candidates &&
-      base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableHardwareOverlays)) {
+      (command_line->HasSwitch(switches::kEnableHardwareOverlays) ||
+       command_line->HasSwitch(switches::kOzoneTestSingleOverlaySupport))) {
     return scoped_ptr<cc::OverlayCandidateValidator>(
         new OverlayCandidateValidatorOzone(widget, overlay_candidates));
   }
 #endif
   return scoped_ptr<cc::OverlayCandidateValidator>();
 }
 
 static bool ShouldCreateGpuOutputSurface(ui::Compositor* compositor) {
 #if defined(OS_CHROMEOS)
   // Software fallback does not happen on Chrome OS.
@@ skipping 389 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