Add a telemetry measurement for property tree performance.

cc/base/switches.cc

 // Copyright (c) 2012 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 "cc/base/switches.h"
 
 #include "base/command_line.h"
 
 namespace cc {
 namespace switches {
@@ skipping 40 matching lines @@
 const char kCompositeToMailbox[] = "composite-to-mailbox";
 
 // Check that property changes during paint do not occur.
 const char kStrictLayerPropertyChangeChecking[] =
     "strict-layer-property-change-checking";
 
 // Virtual viewport for fixed-position elements, scrollbars during pinch.
 const char kEnablePinchVirtualViewport[] = "enable-pinch-virtual-viewport";
 const char kDisablePinchVirtualViewport[] = "disable-pinch-virtual-viewport";
 
+// Ensures that the draw properties computed via the property trees math those
+// computed by CalcDrawProperties.
+const char kEnablePropertyTreeVerification[] =
+    "enable-property-tree-verification";
+
 // Disable partial swap which is needed for some OpenGL drivers / emulators.
 const char kUIDisablePartialSwap[] = "ui-disable-partial-swap";
 
 // Enables the GPU benchmarking extension
 const char kEnableGpuBenchmarking[] = "enable-gpu-benchmarking";
 
 // Renders a border around compositor layers to help debug and study
 // layer compositing.
 const char kShowCompositedLayerBorders[] = "show-composited-layer-borders";
 const char kUIShowCompositedLayerBorders[] = "ui-show-layer-borders";
@@ skipping 39 matching lines @@
 const char kUIShowNonOccludingRects[] = "ui-show-nonoccluding-rects";
 
 // Prevents the layer tree unit tests from timing out.
 const char kCCLayerTreeTestNoTimeout[] = "cc-layer-tree-test-no-timeout";
 
 // Makes pixel tests write their output instead of read it.
 const char kCCRebaselinePixeltests[] = "cc-rebaseline-pixeltests";
 
 }  // namespace switches
 }  // namespace cc