cc: Trace event for veto reason

cc/resources/picture.cc

 // Copyright 2012 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/picture.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 156 matching lines @@
     picture_(picture),
     pixel_refs_(pixel_refs),
     cell_size_(layer_rect.size()) {
 }
 
 Picture::~Picture() {
   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
     TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::Picture", this);
 }
 
-bool Picture::IsSuitableForGpuRasterization() const {
+bool Picture::IsSuitableForGpuRasterization(const char** reason) const {
   DCHECK(picture_);
 
-  // TODO(alokp): SkPicture::suitableForGpuRasterization needs a GrContext.
-  // Ideally this GrContext should be the same as that for rasterizing this
-  // picture. But we are on the main thread while the rasterization context
-  // may be on the compositor or raster thread.
-  // SkPicture::suitableForGpuRasterization is not implemented yet.
-  // Pass a NULL context for now and discuss with skia folks if the context
-  // is really needed.
-  return picture_->suitableForGpuRasterization(NULL);
+  // TODO(hendrikw): SkPicture::suitableForGpuRasterization takes a GrContext.
+  // Currently the GrContext isn't used, and should probably be removed from
+  // skia.
+  return picture_->suitableForGpuRasterization(nullptr, reason);
 }
 
 int Picture::ApproximateOpCount() const {
   DCHECK(picture_);
   return picture_->approximateOpCount();
 }
 
 bool Picture::HasText() const {
   DCHECK(picture_);
   return picture_->hasText();
@@ skipping 315 matching lines @@
   scoped_refptr<base::debug::TracedValue> record_data =
       new base::debug::TracedValue();
   TracedValue::SetIDRef(this, record_data.get(), "picture_id");
   record_data->BeginArray("layer_rect");
   MathUtil::AddToTracedValue(layer_rect_, record_data.get());
   record_data->EndArray();
   return record_data;
 }
 
 }  // namespace cc