Histogram to track missing and incomplete tiles

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 "base/time/time.h"
@@ skipping 262 matching lines @@
     if (*iter && iter->IsReadyToDraw()) {
       const ManagedTileState::TileVersion& tile_version =
           iter->GetTileVersionForDrawing();
       switch (tile_version.mode()) {
         case ManagedTileState::TileVersion::RESOURCE_MODE: {
           gfx::RectF texture_rect = iter.texture_rect();
           gfx::Rect opaque_rect = iter->opaque_rect();
           opaque_rect.Intersect(geometry_rect);
 
           if (iter->contents_scale() != ideal_contents_scale_)
-            append_quads_data->had_incomplete_tile = true;
+            append_quads_data->num_incomplete_tiles++;
 
           TileDrawQuad* quad =
               render_pass->CreateAndAppendDrawQuad<TileDrawQuad>();
           quad->SetNew(shared_quad_state,
                        geometry_rect,
                        opaque_rect,
                        visible_geometry_rect,
                        tile_version.get_resource_id(),
                        texture_rect,
                        iter.texture_size(),
@@ skipping 53 matching lines @@
         SolidColorDrawQuad* quad =
             render_pass->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
         quad->SetNew(shared_quad_state,
                      geometry_rect,
                      visible_geometry_rect,
                      color,
                      false);
       }
 
       append_quads_data->num_missing_tiles++;
-      append_quads_data->had_incomplete_tile = true;
       append_quads_data->approximated_visible_content_area +=
           visible_geometry_rect.width() * visible_geometry_rect.height();
       ++missing_tile_count;
       continue;
     }
 
     if (iter->priority(ACTIVE_TREE).resolution != HIGH_RESOLUTION) {
       append_quads_data->approximated_visible_content_area +=
           visible_geometry_rect.width() * visible_geometry_rect.height();
     }
@@ skipping 1261 matching lines @@
   return iterator_index_ < iterators_.size();
 }
 
 bool PictureLayerImpl::LayerEvictionTileIterator::IsCorrectType(
     PictureLayerTiling::TilingEvictionTileIterator* it) const {
   return it->get_type() == iteration_stage_ &&
          (**it)->required_for_activation() == required_for_activation_;
 }
 
 }  // namespace cc