Add builders for tracing event's structural arguments

cc/resources/picture_pile_base.cc

Index: cc/resources/picture_pile_base.cc
diff --git a/cc/resources/picture_pile_base.cc b/cc/resources/picture_pile_base.cc
index 55209dbf86ff1d2220b56f01fd35690ba9944943..146c886d4780de0efc143c79a1eda79f7438d4cc 100644
--- a/cc/resources/picture_pile_base.cc
+++ b/cc/resources/picture_pile_base.cc
@@ -8,6 +8,7 @@
 #include <set>
 #include <vector>
 
+#include "base/debug/trace_event_argument.h"
 #include "base/logging.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
@@ -198,8 +199,7 @@ gfx::Rect PicturePileBase::PadRect(const gfx::Rect& rect) {
   return padded_rect;
 }
 
-scoped_ptr<base::Value> PicturePileBase::AsValue() const {
-  scoped_ptr<base::ListValue> pictures(new base::ListValue());
+void PicturePileBase::AsValueInto(base::debug::TracedValue* pictures) const {
   gfx::Rect tiling_rect(tiling_.tiling_size());
   std::set<void*> appended_pictures;
   bool include_borders = true;
@@ -213,10 +213,9 @@ scoped_ptr<base::Value> PicturePileBase::AsValue() const {
     Picture* picture = map_iter->second.GetPicture();
     if (picture && (appended_pictures.count(picture) == 0)) {
       appended_pictures.insert(picture);
-      pictures->Append(TracedValue::CreateIDRef(picture).release());
+      TracedValue::AppendIDRef(picture, pictures);
     }
   }
-  return pictures.PassAs<base::Value>();
 }
 
 PicturePileBase::PictureInfo::PictureInfo() : last_frame_number_(0) {}