cc: Report only on active tiles in tracing.

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index b264b4754696f60d1590b9885d74b8bfee336fd1..27df613dabe12af0ab6ec2adcd1942214417ac1d 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -731,10 +731,13 @@ void TileManager::BasicStateAsValueInto(base::debug::TracedValue* state) const {
   state->EndDictionary();
 }
 
-void TileManager::AllTilesAsValueInto(base::debug::TracedValue* state) const {
+void TileManager::AllTilesAsValueInto(
+    base::debug::TracedValue* state,
+    const std::set<const Tile*>& active_tiles) const {
   for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
+    bool is_active = active_tiles.count(it->second) != 0;
     state->BeginDictionary();
-    it->second->AsValueInto(state);
+    it->second->AsValueInto(state, is_active);
     state->EndDictionary();
   }
 }