Correct DisplayItemList::ApproximateOpCount() for flattened picture

cc/playback/recording_source.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 "cc/playback/recording_source.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
@@ skipping 86 matching lines @@
   Region newly_exposed_region(new_recorded_viewport);
   newly_exposed_region.Subtract(old_recorded_viewport);
   invalidation->Union(newly_exposed_region);
 
   Region no_longer_exposed_region(old_recorded_viewport);
   no_longer_exposed_region.Subtract(new_recorded_viewport);
   invalidation->Union(no_longer_exposed_region);
 }
 
 void RecordingSource::FinishDisplayItemListUpdate() {
+  TRACE_EVENT0("cc", "RecordingSource::FinishDisplayItemListUpdate");
   DetermineIfSolidColor();
   display_list_->EmitTraceSnapshot();
   if (generate_discardable_images_metadata_)
     display_list_->GenerateDiscardableImagesMetadata();
 }
 
 void RecordingSource::SetNeedsDisplayRect(const gfx::Rect& layer_rect) {
   if (!layer_rect.IsEmpty()) {
     // Clamp invalidation to the layer bounds.
     invalidation_.Union(gfx::IntersectRects(layer_rect, gfx::Rect(size_)));
@@ skipping 103 matching lines @@
 }
 
 void RecordingSource::DetermineIfSolidColor() {
   DCHECK(display_list_);
   is_solid_color_ = false;
   solid_color_ = SK_ColorTRANSPARENT;
 
   if (!display_list_->ShouldBeAnalyzedForSolidColor())
     return;
 
+  TRACE_EVENT1("cc", "RecordingSource::DetermineIfSolidColor", "opcount",
+               display_list_->ApproximateOpCount());
   gfx::Size layer_size = GetSize();
   skia::AnalysisCanvas canvas(layer_size.width(), layer_size.height());
   display_list_->Raster(&canvas, nullptr, gfx::Rect(), 1.f);
   is_solid_color_ = canvas.GetColorIfSolid(&solid_color_);
 }
 
 void RecordingSource::Clear() {
   recorded_viewport_ = gfx::Rect();
   display_list_ = nullptr;
   painter_reported_memory_usage_ = 0;
   is_solid_color_ = false;
 }
 
 }  // namespace cc