Revert of Add builders for tracing event's structural arguments

cc/resources/picture_layer_tiling_set.cc

Index: cc/resources/picture_layer_tiling_set.cc
diff --git a/cc/resources/picture_layer_tiling_set.cc b/cc/resources/picture_layer_tiling_set.cc
index 0a882d0257382e9b43c452281453ebeb3d07cd90..bbe4070eaf53b3dd798af9ad76653ee29fcfe84c 100644
--- a/cc/resources/picture_layer_tiling_set.cc
+++ b/cc/resources/picture_layer_tiling_set.cc
@@ -317,12 +317,11 @@
     tilings_[i]->DidBecomeRecycled();
 }
 
-void PictureLayerTilingSet::AsValueInto(base::debug::TracedValue* state) const {
-  for (size_t i = 0; i < tilings_.size(); ++i) {
-    state->BeginDictionary();
-    tilings_[i]->AsValueInto(state);
-    state->EndDictionary();
-  }
+scoped_ptr<base::Value> PictureLayerTilingSet::AsValue() const {
+  scoped_ptr<base::ListValue> state(new base::ListValue());
+  for (size_t i = 0; i < tilings_.size(); ++i)
+    state->Append(tilings_[i]->AsValue().release());
+  return state.PassAs<base::Value>();
 }
 
 size_t PictureLayerTilingSet::GPUMemoryUsageInBytes() const {