cc: Consider visible rect for update tile priority early out.

cc/resources/picture_layer_tiling.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_layer_tiling.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <set>
@@ skipping 522 matching lines @@
   skewport.Union(visible_rect_in_content_space);
   return skewport;
 }
 
 void PictureLayerTiling::UpdateTilePriorities(
     WhichTree tree,
     const gfx::Rect& viewport_in_layer_space,
     float ideal_contents_scale,
     double current_frame_time_in_seconds,
     const Occlusion& occlusion_in_layer_space) {
-  if (!NeedsUpdateForFrameAtTime(current_frame_time_in_seconds)) {
+  if (!NeedsUpdateForFrameAtTimeAndViewport(current_frame_time_in_seconds,
+                                            viewport_in_layer_space)) {
     // This should never be zero for the purposes of has_ever_been_updated().
     DCHECK_NE(current_frame_time_in_seconds, 0.0);
     return;
   }
 
   gfx::Rect visible_rect_in_content_space =
       gfx::ScaleToEnclosingRect(viewport_in_layer_space, contents_scale_);
 
   if (tiling_size().IsEmpty()) {
     last_impl_frame_time_in_seconds_ = current_frame_time_in_seconds;
+    last_viewport_in_layer_space_ = viewport_in_layer_space;
     last_visible_rect_in_content_space_ = visible_rect_in_content_space;
     return;
   }
 
   size_t max_tiles_for_interest_area = client_->GetMaxTilesForInterestArea();
 
   gfx::Size tile_size = tiling_data_.max_texture_size();
   int64 eventually_rect_area =
       max_tiles_for_interest_area * tile_size.width() * tile_size.height();
 
   gfx::Rect skewport = ComputeSkewport(current_frame_time_in_seconds,
                                        visible_rect_in_content_space);
   DCHECK(skewport.Contains(visible_rect_in_content_space));
 
   gfx::Rect eventually_rect =
       ExpandRectEquallyToAreaBoundedBy(visible_rect_in_content_space,
                                        eventually_rect_area,
                                        gfx::Rect(tiling_size()),
                                        &expansion_cache_);
 
   DCHECK(eventually_rect.IsEmpty() ||
          gfx::Rect(tiling_size()).Contains(eventually_rect))
       << "tiling_size: " << tiling_size().ToString()
       << " eventually_rect: " << eventually_rect.ToString();
 
   SetLiveTilesRect(eventually_rect);
 
   last_impl_frame_time_in_seconds_ = current_frame_time_in_seconds;
+  last_viewport_in_layer_space_ = viewport_in_layer_space;
   last_visible_rect_in_content_space_ = visible_rect_in_content_space;
 
   eviction_tiles_cache_valid_ = false;
 
   TilePriority now_priority(resolution_, TilePriority::NOW, 0);
   float content_to_screen_scale = ideal_contents_scale / contents_scale_;
 
   // Assign now priority to all visible tiles.
   bool include_borders = false;
   has_visible_rect_tiles_ = false;
@@ skipping 599 matching lines @@
   DCHECK(*this);
   do {
     ++current_eviction_tiles_index_;
   } while (current_eviction_tiles_index_ != eviction_tiles_->size() &&
            !(*eviction_tiles_)[current_eviction_tiles_index_]->HasResources());
 
   return *this;
 }
 
 }  // namespace cc