cc: Do not ignore layers without valid priorities during eviction.

cc/resources/picture_layer_tiling.h

Index: cc/resources/picture_layer_tiling.h
diff --git a/cc/resources/picture_layer_tiling.h b/cc/resources/picture_layer_tiling.h
index 17da548c916ae4e8e9903642f953a8f70aa5335d..610ad5a2fb312aab3fa0801e867823e077cacb91 100644
--- a/cc/resources/picture_layer_tiling.h
+++ b/cc/resources/picture_layer_tiling.h
@@ -123,7 +123,9 @@ class CC_EXPORT PictureLayerTiling {
     TilingEvictionTileIterator();
     TilingEvictionTileIterator(PictureLayerTiling* tiling,
                                TreePriority tree_priority,
-                               EvictionCategory category);
+                               EvictionCategory category,
+                               bool use_tile_priority_rects,
+                               bool use_twin_tile_priority_rects);
     ~TilingEvictionTileIterator();
 
     operator bool() const;
@@ -181,7 +183,7 @@ class CC_EXPORT PictureLayerTiling {
 
   void UpdateAllTilePrioritiesForTesting() {
     for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
-      UpdateTileAndTwinPriority(it->second.get());
+      UpdateTileAndTwinPriority(it->second.get(), true, true);
   }
 
   std::vector<scoped_refptr<Tile>> AllRefTilesForTesting() const {
@@ -320,16 +322,23 @@ class CC_EXPORT PictureLayerTiling {
                             const gfx::Rect& visible_rect_in_content_space)
       const;
 
-  void UpdateEvictionCacheIfNeeded(TreePriority tree_priority);
-  const std::vector<Tile*>* GetEvictionTiles(TreePriority tree_priority,
-                                             EvictionCategory category);
+  void UpdateEvictionCacheIfNeeded(TreePriority tree_priority,
+                                   bool tiling_has_valid_tile_priorities,
+                                   bool twin_tiling_has_valid_tile_priorities);
+  const std::vector<Tile*>* GetEvictionTiles(
+      TreePriority tree_priority,
+      EvictionCategory category,
+      bool tiling_has_valid_tile_priorities,
+      bool twin_tiling_has_valid_tile_priorities);
 
   void Invalidate(const Region& layer_region);
 
   void DoInvalidate(const Region& layer_region,
                     bool recreate_invalidated_tiles);
 
-  void UpdateTileAndTwinPriority(Tile* tile) const;
+  void UpdateTileAndTwinPriority(Tile* tile,
+                                 bool use_tile_priority_rects,
+                                 bool use_twin_tile_priority_rects) const;
   void UpdateTilePriority(Tile* tile) const;
 
   // Given properties.