Speculative revert by sheriff

cc/resources/drawing_display_item.cc

 // Copyright 2014 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/resources/drawing_display_item.h"
 
 #include <string>
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 16 matching lines @@
 void DrawingDisplayItem::Raster(SkCanvas* canvas,
                                 SkDrawPictureCallback* callback) const {
   canvas->save();
   if (callback)
     picture_->playback(canvas, callback);
   else
     canvas->drawPicture(picture_.get());
   canvas->restore();
 }
 
+void DrawingDisplayItem::RasterForTracing(SkCanvas* canvas) const {
+  canvas->save();
+  // The picture debugger in about:tracing doesn't drill down into |drawPicture|
+  // operations. Calling |playback()| rather than |drawPicture()| causes the
+  // skia operations in |picture_| to appear individually in the picture
+  // produced for tracing rather than being hidden inside a drawPicture
+  // operation.
+  picture_->playback(canvas);
+  canvas->restore();
+}
+
 bool DrawingDisplayItem::IsSuitableForGpuRasterization() const {
   return picture_->suitableForGpuRasterization(NULL);
 }
 
 int DrawingDisplayItem::ApproximateOpCount() const {
   return picture_->approximateOpCount();
 }
 
 size_t DrawingDisplayItem::PictureMemoryUsage() const {
   DCHECK(picture_);
   return SkPictureUtils::ApproximateBytesUsed(picture_.get());
 }
 
 void DrawingDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->BeginDictionary();
   array->SetString("name", "DrawingDisplayItem");
   array->SetString(
       "cullRect",
       base::StringPrintf("[%f,%f,%f,%f]", picture_->cullRect().x(),
                          picture_->cullRect().y(), picture_->cullRect().width(),
                          picture_->cullRect().height()));
   std::string b64_picture;
   PictureDebugUtil::SerializeAsBase64(picture_.get(), &b64_picture);
   array->SetString("skp64", b64_picture);
   array->EndDictionary();
 }
 
 }  // namespace cc