cc: Add some useful layer data to traces.

cc/layers/picture_layer_impl.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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 1393 matching lines @@
 
 void PictureLayerImpl::AsValueInto(base::debug::TracedValue* state) const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   LayerImpl::AsValueInto(state);
   state->SetDouble("ideal_contents_scale", ideal_contents_scale_);
   state->SetDouble("geometry_contents_scale", MaximumTilingContentsScale());
   state->BeginArray("tilings");
   tilings_->AsValueInto(state);
   state->EndArray();
 
+  state->BeginArray("tile_priority_rect");
+  MathUtil::AddToTracedValue(GetViewportForTilePriorityInContentSpace(), state);
+  state->EndArray();
+
+  state->BeginArray("visible_rect");
+  MathUtil::AddToTracedValue(visible_content_rect(), state);
+  state->EndArray();
+
   state->BeginArray("pictures");
   pile_->AsValueInto(state);
   state->EndArray();
 
   state->BeginArray("invalidation");
   invalidation_.AsValueInto(state);
   state->EndArray();
 
   state->BeginArray("coverage_tiles");
   for (PictureLayerTilingSet::CoverageIterator iter(tilings_.get(),
@@ skipping 342 matching lines @@
       PictureLayerTilingSet::TilingRange tiling_range = CurrentTilingRange();
       size_t current_tiling_range_offset = current_tiling_ - tiling_range.start;
       return tiling_range.end - 1 - current_tiling_range_offset;
     }
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace cc