Add a telemetry measurement for property tree performance.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 255 matching lines @@
       std::string top_threshold_str =
           cmd->GetSwitchValueASCII(cc::switches::kTopControlsHideThreshold);
       double hide_threshold;
       if (base::StringToDouble(top_threshold_str, &hide_threshold) &&
           hide_threshold >= 0.f && hide_threshold <= 1.f)
         settings.top_controls_hide_threshold = hide_threshold;
   }
 
   settings.use_pinch_virtual_viewport =
       cmd->HasSwitch(cc::switches::kEnablePinchVirtualViewport);
+  settings.verify_property_trees =
+      cmd->HasSwitch(cc::switches::kEnablePropertyTreeVerification);
   settings.renderer_settings.allow_antialiasing &=
       !cmd->HasSwitch(cc::switches::kDisableCompositedAntialiasing);
   settings.single_thread_proxy_scheduler =
       compositor_deps_->UseSingleThreadScheduler();
 
   // These flags should be mirrored by UI versions in ui/compositor/.
   settings.initial_debug_state.show_debug_borders =
       cmd->HasSwitch(cc::switches::kShowCompositedLayerBorders);
   settings.initial_debug_state.show_fps_counter =
       cmd->HasSwitch(cc::switches::kShowFPSCounter);
@@ skipping 597 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       compositor_deps_->GetSharedMainThreadContextProvider();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content