cc: Report only on active tiles in tracing.

cc/layers/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/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/json/json_reader.h"
 #include "base/strings/stringprintf.h"
@@ skipping 1382 matching lines @@
 }
 
 void LayerImpl::RemoveDependentNeedsPushProperties() {
   num_dependents_need_push_properties_--;
   DCHECK_GE(num_dependents_need_push_properties_, 0);
 
   if (!parent_should_know_need_push_properties() && parent_)
       parent_->RemoveDependentNeedsPushProperties();
 }
 
+void LayerImpl::GetAllTilesForTracing(std::set<const Tile*>* tiles) const {
+}
+
 void LayerImpl::AsValueInto(base::debug::TracedValue* state) const {
   TracedValue::MakeDictIntoImplicitSnapshotWithCategory(
       TRACE_DISABLED_BY_DEFAULT("cc.debug"),
       state,
       "cc::LayerImpl",
       LayerTypeAsString(),
       this);
   state->SetInteger("layer_id", id());
   state->BeginDictionary("bounds");
   MathUtil::AddToTracedValue(bounds_, state);
@@ skipping 122 matching lines @@
 }
 
 void LayerImpl::NotifyAnimationFinished(
     base::TimeTicks monotonic_time,
     Animation::TargetProperty target_property) {
   if (target_property == Animation::ScrollOffset)
     layer_tree_impl_->InputScrollAnimationFinished();
 }
 
 }  // namespace cc