cc: Report only on active tiles in tracing.

cc/layers/picture_layer_impl.cc

 // Copyright 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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
+#include <set>
 
 #include "base/debug/trace_event_argument.h"
 #include "base/time/time.h"
 #include "cc/base/math_util.h"
 #include "cc/base/util.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/debug/micro_benchmark_impl.h"
 #include "cc/debug/traced_value.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/output/begin_frame_args.h"
@@ skipping 1378 matching lines @@
   ideal_source_scale_ = std::max(ideal_source_scale, min_source_scale);
 }
 
 void PictureLayerImpl::GetDebugBorderProperties(
     SkColor* color,
     float* width) const {
   *color = DebugColors::TiledContentLayerBorderColor();
   *width = DebugColors::TiledContentLayerBorderWidth(layer_tree_impl());
 }
 
+void PictureLayerImpl::GetAllTilesForTracing(
+    std::set<const Tile*>* tiles) const {
+  if (!tilings_)
+    return;
+
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i)
+    tilings_->tiling_at(i)->GetAllTilesForTracing(tiles);
+}
+
 void PictureLayerImpl::AsValueInto(base::debug::TracedValue* state) const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   LayerImpl::AsValueInto(state);
   state->SetDouble("ideal_contents_scale", ideal_contents_scale_);
   state->SetDouble("geometry_contents_scale", MaximumTilingContentsScale());
   state->BeginArray("tilings");
   tilings_->AsValueInto(state);
   state->EndArray();
 
   state->BeginArray("pictures");
@@ skipping 347 matching lines @@
       PictureLayerTilingSet::TilingRange tiling_range = CurrentTilingRange();
       size_t current_tiling_range_offset = current_tiling_ - tiling_range.start;
       return tiling_range.end - 1 - current_tiling_range_offset;
     }
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace cc