Adding a metric to track only the checkerboarding.

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 <cmath>
 #include <limits>
 #include <set>
@@ skipping 333 matching lines @@
                      color,
                      false);
       }
 
       if (geometry_rect.Intersects(scaled_viewport_for_tile_priority)) {
         append_quads_data->num_missing_tiles++;
         ++missing_tile_count;
       }
       append_quads_data->approximated_visible_content_area +=
           visible_geometry_rect.width() * visible_geometry_rect.height();
+      append_quads_data->checkerboarded_visible_content_area +=
+          visible_geometry_rect.width() * visible_geometry_rect.height();
       continue;
     }
 
     if (iter.resolution() != HIGH_RESOLUTION) {
       append_quads_data->approximated_visible_content_area +=
           visible_geometry_rect.width() * visible_geometry_rect.height();
     }
 
     // If we have a draw quad, but it's not low resolution, then
     // mark that we've used something other than low res to draw.
@@ skipping 869 matching lines @@
 
 bool PictureLayerImpl::IsOnActiveOrPendingTree() const {
   return !layer_tree_impl()->IsRecycleTree();
 }
 
 bool PictureLayerImpl::HasValidTilePriorities() const {
   return IsOnActiveOrPendingTree() && IsDrawnRenderSurfaceLayerListMember();
 }
 
 }  // namespace cc