Trace picture piles on layers

cc/debug/traced_picture.cc

 // Copyright (c) 2013 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/debug/traced_picture.h"
 
 #include "base/json/json_writer.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "cc/debug/traced_value.h"
@@ skipping 10 matching lines @@
 scoped_ptr<base::debug::ConvertableToTraceFormat>
     TracedPicture::AsTraceablePicture(Picture* picture) {
   TracedPicture* ptr = new TracedPicture(picture);
   scoped_ptr<TracedPicture> result(ptr);
   return result.PassAs<base::debug::ConvertableToTraceFormat>();
 }
 
 void TracedPicture::AppendAsTraceFormat(std::string* out) const {
   std::string encoded_picture;
   picture_->AsBase64String(&encoded_picture);
-  out->append("\"");
+  out->append("{");
+  out->append("\"layer_rect\": [");
+  base::StringAppendF(
+      out, "%i,%i,%i,%i",
+      picture_->LayerRect().x(), picture_->LayerRect().y(),

[vmpstr2, 2013/05/14 18:16:09]

picture's layer rect is encoded as a part of AsBase64String. Is the reason for
putting it here separately just so we can tell what the layer is without
decoding the picture? (I'm just trying to catch up on understanding)

+      picture_->LayerRect().width(), picture_->LayerRect().height());
+  out->append("],");
+  out->append("\"data_b64\": \"");
   out->append(encoded_picture);
-  out->append("\"");
+  out->append("\"}");
 }
 
 }  // namespace cc