Add initial implementation of cc::Surfaces backend for exo.

components/exo/display.cc

 // Copyright 2015 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 "components/exo/display.h"
 
 #include <iterator>
 #include <utility>
 
 #include "ash/wm/common/wm_shell_window_ids.h"
+#include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "components/exo/shared_memory.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/sub_surface.h"
 #include "components/exo/surface.h"
 #include "ui/views/widget/widget.h"
 
 #if defined(USE_OZONE)
 #include <GLES2/gl2extchromium.h>
 #include "components/exo/buffer.h"
 #include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "ui/aura/env.h"
 #endif
 
 namespace exo {
 
+const char kUseExoSurfaceLayer[] = "use-exo-surface-layer";
+
 ////////////////////////////////////////////////////////////////////////////////
 // Display, public:
 
-Display::Display() {}
+Display::Display() {
+  Surface::SetUseSurfaceLayer(
+      base::CommandLine::ForCurrentProcess()->HasSwitch(kUseExoSurfaceLayer));
+}
 
 Display::~Display() {}
 
 std::unique_ptr<Surface> Display::CreateSurface() {
   TRACE_EVENT0("exo", "Display::CreateSurface");
 
   return base::WrapUnique(new Surface);
 }
 
 std::unique_ptr<SharedMemory> Display::CreateSharedMemory(
@@ skipping 114 matching lines @@
 
   if (surface->HasSurfaceDelegate()) {
     DLOG(ERROR) << "Surface has already been assigned a role";
     return nullptr;
   }
 
   return base::WrapUnique(new SubSurface(surface, parent));
 }
 
 }  // namespace exo