Update from https://crrev.com/314320

cc/resources/display_item_list.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/display_item_list.h"
 
 #include <string>
 
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
@@ skipping 53 matching lines @@
 
   return total_size;
 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat> DisplayItemList::AsValue()
     const {
   scoped_refptr<base::debug::TracedValue> state =
       new base::debug::TracedValue();
 
   state->SetInteger("length", items_.size());
+  state->BeginArray("params.items");
+  for (const DisplayItem* item : items_) {
+    item->AsValueInto(state.get());
+  }
+  state->EndArray();
   state->SetValue("params.layer_rect",
                   MathUtil::AsValue(layer_rect_).release());
 
   SkPictureRecorder recorder;
   SkCanvas* canvas =
       recorder.beginRecording(layer_rect_.width(), layer_rect_.height());
   canvas->translate(-layer_rect_.x(), -layer_rect_.y());
   canvas->clipRect(gfx::RectToSkRect(layer_rect_));
   for (size_t i = 0; i < items_.size(); ++i)
     items_[i]->RasterForTracing(canvas);
   skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder.endRecording());
 
   std::string b64_picture;
   PictureDebugUtil::SerializeAsBase64(picture.get(), &b64_picture);
   state->SetString("skp64", b64_picture);
 
   return state;
 }
 
 void DisplayItemList::EmitTraceSnapshot() const {
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("cc.debug") "," TRACE_DISABLED_BY_DEFAULT(
           "devtools.timeline.picture"),
       "cc::DisplayItemList", this, AsValue());
 }
 
 }  // namespace cc