cc: Report only on active tiles in tracing.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 3127 matching lines @@
     FrameData* frame,
     base::debug::TracedValue* state) const {
   if (this->pending_tree_) {
     state->BeginDictionary("activation_state");
     ActivationStateAsValueInto(state);
     state->EndDictionary();
   }
   state->BeginDictionary("device_viewport_size");
   MathUtil::AddToTracedValue(device_viewport_size_, state);
   state->EndDictionary();
+
+  std::set<const Tile*> tiles;
+  active_tree_->GetAllTilesForTracing(&tiles);
+  if (pending_tree_)
+    pending_tree_->GetAllTilesForTracing(&tiles);
+
+  state->BeginArray("active_tiles");
+  for (std::set<const Tile*>::const_iterator it = tiles.begin();
+       it != tiles.end();
+       ++it) {
+    const Tile* tile = *it;
+
+    state->BeginDictionary();
+    tile->AsValueInto(state);
+    state->EndDictionary();
+  }
+  state->EndArray();
+
   if (tile_manager_) {
-    state->BeginArray("tiles");
-    tile_manager_->AllTilesAsValueInto(state);
-    state->EndArray();
-
     state->BeginDictionary("tile_manager_basic_state");
     tile_manager_->BasicStateAsValueInto(state);
     state->EndDictionary();
   }
   state->BeginDictionary("active_tree");
   active_tree_->AsValueInto(state);
   state->EndDictionary();
   if (pending_tree_) {
     state->BeginDictionary("pending_tree");
     pending_tree_->AsValueInto(state);
@@ skipping 175 matching lines @@
 }
 
 void LayerTreeHostImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   std::vector<PictureLayerImpl*>::iterator it =
       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
   DCHECK(it != picture_layers_.end());
   picture_layers_.erase(it);
 }
 
 }  // namespace cc