cc: Reset raster scale if we didn't sync high res tiling.

cc/resources/picture_layer_tiling_set.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_set.h"
 
 #include <limits>
 
 namespace cc {
 
@@ skipping 18 matching lines @@
 
 PictureLayerTilingSet::~PictureLayerTilingSet() {
 }
 
 void PictureLayerTilingSet::SetClient(PictureLayerTilingClient* client) {
   client_ = client;
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->SetClient(client_);
 }
 
-void PictureLayerTilingSet::SyncTilings(
-    const PictureLayerTilingSet& other,
-    const gfx::Size& new_layer_bounds,
-    const Region& layer_invalidation,
-    float minimum_contents_scale) {
+bool PictureLayerTilingSet::SyncTilings(const PictureLayerTilingSet& other,
+                                        const gfx::Size& new_layer_bounds,
+                                        const Region& layer_invalidation,
+                                        float minimum_contents_scale) {
   if (new_layer_bounds.IsEmpty()) {
     RemoveAllTilings();
     layer_bounds_ = new_layer_bounds;
-    return;
+    return false;
   }
 
   tilings_.reserve(other.tilings_.size());
 
   // Remove any tilings that aren't in |other| or don't meet the minimum.
   for (size_t i = 0; i < tilings_.size(); ++i) {
     float scale = tilings_[i]->contents_scale();
     if (scale >= minimum_contents_scale && !!other.TilingAtScale(scale))
       continue;
     // Swap with the last element and remove it.
     tilings_.swap(tilings_.begin() + i, tilings_.end() - 1);
     tilings_.pop_back();
     --i;
   }
 
+  bool have_high_res_tiling = false;
+
   // Add any missing tilings from |other| that meet the minimum.
   for (size_t i = 0; i < other.tilings_.size(); ++i) {
     float contents_scale = other.tilings_[i]->contents_scale();
     if (contents_scale < minimum_contents_scale)
       continue;
     if (PictureLayerTiling* this_tiling = TilingAtScale(contents_scale)) {
       this_tiling->set_resolution(other.tilings_[i]->resolution());
 
       // These two calls must come before updating the pile, because they may
       // destroy tiles that the new pile cannot raster.
       this_tiling->SetLayerBounds(new_layer_bounds);
       this_tiling->Invalidate(layer_invalidation);
 
       this_tiling->UpdateTilesToCurrentPile();
       this_tiling->CreateMissingTilesInLiveTilesRect();
+      if (this_tiling->resolution() == HIGH_RESOLUTION)
+        have_high_res_tiling = true;
 
       DCHECK(this_tiling->tile_size() ==
              client_->CalculateTileSize(this_tiling->TilingRect().size()));
       continue;
     }
     scoped_ptr<PictureLayerTiling> new_tiling = PictureLayerTiling::Create(
         contents_scale,
         new_layer_bounds,
         client_);
     new_tiling->set_resolution(other.tilings_[i]->resolution());
+    if (new_tiling->resolution() == HIGH_RESOLUTION)
+      have_high_res_tiling = true;
     tilings_.push_back(new_tiling.Pass());
   }
   tilings_.sort(LargestToSmallestScaleFunctor());
 
   layer_bounds_ = new_layer_bounds;
+  return have_high_res_tiling;
 }
 
 void PictureLayerTilingSet::RemoveTilesInRegion(const Region& region) {
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->RemoveTilesInRegion(region);
 }
 
 void PictureLayerTilingSet::SetCanUseLCDText(bool can_use_lcd_text) {
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->SetCanUseLCDText(can_use_lcd_text);
@@ skipping 241 matching lines @@
 }
 
 size_t PictureLayerTilingSet::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (size_t i = 0; i < tilings_.size(); ++i)
     amount += tilings_[i]->GPUMemoryUsageInBytes();
   return amount;
 }
 
 }  // namespace cc