cc: Fix PictureLayerImpl::SanityCheck condition

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 658 matching lines @@
 
   SanityCheckTilingState();
 }
 
 void PictureLayerImpl::SyncTiling(
     const PictureLayerTiling* tiling) {
   if (!CanHaveTilingWithScale(tiling->contents_scale()))
     return;
   tilings_->AddTiling(tiling->contents_scale());
 
-  if (!layer_tree_impl()->needs_update_draw_properties()) {
+  if (!layer_tree_impl()->needs_update_draw_properties() &&
+      should_update_tile_priorities_) {
     // When the tree is up to date, the set of tilings must either be empty or

[enne (OOO), 2014/04/28 23:45:28]

Can you just move this comment and check into the block below that has the same
conditional?

[boliu, 2014/04/28 23:50:39]

Done.

     // contain at least one high resolution tiling.  (If it is up to date,
     // then it would be invalid to sync a tiling if it is the first tiling
     // on the layer, since there would be no high resolution tiling.)
     SanityCheckTilingState();
     // TODO(enne): temporary sanity CHECK for http://crbug.com/358350
     CHECK_GT(tilings_->num_tilings(), 1u);
   }
 
   // If this tree needs update draw properties, then the tiling will
   // get updated prior to drawing or activation.  If this tree does not
@@ skipping 826 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