cc: Use reverse spiral iterator in tiling eviction.

cc/resources/eviction_tile_priority_queue.cc

Index: cc/resources/eviction_tile_priority_queue.cc
diff --git a/cc/resources/eviction_tile_priority_queue.cc b/cc/resources/eviction_tile_priority_queue.cc
index 9f05e816764613ee7424cff8bff3d6f6376e8430..776a6f4c0334a0fcf20fa2ba563a41c616c408dd 100644
--- a/cc/resources/eviction_tile_priority_queue.cc
+++ b/cc/resources/eviction_tile_priority_queue.cc
@@ -93,8 +93,7 @@ void EvictionTilePriorityQueue::Build(
            paired_layers.begin();
        it != paired_layers.end();
        ++it) {
-    paired_queues_.push_back(
-        make_scoped_ptr(new PairedPictureLayerQueue(*it, tree_priority_)));
+    paired_queues_.push_back(make_scoped_ptr(new PairedPictureLayerQueue(*it)));
   }
 
   paired_queues_.make_heap(EvictionOrderComparator(tree_priority_));
@@ -126,17 +125,14 @@ EvictionTilePriorityQueue::PairedPictureLayerQueue::PairedPictureLayerQueue() {
 }
 
 EvictionTilePriorityQueue::PairedPictureLayerQueue::PairedPictureLayerQueue(
-    const PictureLayerImpl::Pair& layer_pair,
-    TreePriority tree_priority)
+    const PictureLayerImpl::Pair& layer_pair)
     : active_iterator(
           layer_pair.active
-              ? PictureLayerImpl::LayerEvictionTileIterator(layer_pair.active,
-                                                            tree_priority)
+              ? PictureLayerImpl::LayerEvictionTileIterator(layer_pair.active)
               : PictureLayerImpl::LayerEvictionTileIterator()),
       pending_iterator(
           layer_pair.pending
-              ? PictureLayerImpl::LayerEvictionTileIterator(layer_pair.pending,
-                                                            tree_priority)
+              ? PictureLayerImpl::LayerEvictionTileIterator(layer_pair.pending)
               : PictureLayerImpl::LayerEvictionTileIterator()) {
 }