Mac: Add command line flag to disable AVFoundation layers

gpu/ipc/service/image_transport_surface_overlay_mac.mm

 // 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 "gpu/ipc/service/image_transport_surface_overlay_mac.h"
 
 #include <CoreGraphics/CoreGraphics.h>
 #include <IOSurface/IOSurface.h>
 #include <OpenGL/CGLRenderers.h>
 #include <OpenGL/CGLTypes.h>
 #include <OpenGL/gl.h>
 #include <stddef.h>
 
 #include <algorithm>
 
 // This type consistently causes problem on Mac, and needs to be dealt with
 // in a systemic way.
 // http://crbug.com/517208
 #ifndef GL_OES_EGL_image
 typedef void* GLeglImageOES;
 #endif
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/command_line.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "gpu/ipc/common/gpu_messages.h"
 #include "gpu/ipc/service/gpu_channel_manager.h"
 #include "gpu/ipc/service/gpu_channel_manager_delegate.h"
 #include "ui/accelerated_widget_mac/ca_layer_tree_coordinator.h"
 #include "ui/accelerated_widget_mac/io_surface_context.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/base/cocoa/remote_layer_api.h"
+#include "ui/base/ui_base_switches.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/swap_result.h"
 #include "ui/gfx/transform.h"
 #include "ui/gl/ca_renderer_layer_params.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_fence.h"
 #include "ui/gl/gl_image_io_surface.h"
 #include "ui/gl/gpu_switching_manager.h"
 #include "ui/gl/scoped_api.h"
 #include "ui/gl/scoped_cgl.h"
@@ skipping 15 matching lines @@
 namespace gpu {
 
 ImageTransportSurfaceOverlayMac::ImageTransportSurfaceOverlayMac(
     GpuCommandBufferStub* stub)
     : stub_(stub->AsWeakPtr()),
       use_remote_layer_api_(ui::RemoteLayerAPISupported()),
       scale_factor_(1),
       gl_renderer_id_(0) {
   ui::GpuSwitchingManager::GetInstance()->AddObserver(this);
 
-  bool disable_av_sample_buffer_display_layer =
-      stub_->GetFeatureInfo()
-          ->workarounds()
-          .disable_av_sample_buffer_display_layer;
+  static bool av_disabled_at_command_line =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableAVFoundationOverlays);
+
+  bool allow_av_sample_buffer_display_layer =
+      !av_disabled_at_command_line &&
+      !stub_->GetFeatureInfo()
+           ->workarounds()
+           .disable_av_sample_buffer_display_layer;
 
   ca_layer_tree_coordinator_.reset(new ui::CALayerTreeCoordinator(
-      use_remote_layer_api_, !disable_av_sample_buffer_display_layer));
+      use_remote_layer_api_, allow_av_sample_buffer_display_layer));
 }
 
 ImageTransportSurfaceOverlayMac::~ImageTransportSurfaceOverlayMac() {
   ui::GpuSwitchingManager::GetInstance()->RemoveObserver(this);
   if (stub_.get()) {
     stub_->SetLatencyInfoCallback(
         base::Callback<void(const std::vector<ui::LatencyInfo>&)>());
   }
   Destroy();
 }
@@ skipping 298 matching lines @@
   gl_renderer_id_ = context_renderer_id & kCGLRendererIDMatchingMask;
 
   // Post a task holding a reference to the new GL context. The reason for
   // this is to avoid creating-then-destroying the context for every image
   // transport surface that is observing the GPU switch.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&IOSurfaceContextNoOp, context_on_new_gpu));
 }
 
 }  // namespace gpu