cc: Fix a bug in tile manager raster tile iterator.

cc/resources/tile_manager.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/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 1428 matching lines @@
 
   Tile* a_tile = **a_pair.first;
   Tile* b_tile = **b_pair.first;
 
   const TilePriority& a_priority =
       a_tile->priority_for_tree_priority(tree_priority_);
   const TilePriority& b_priority =
       b_tile->priority_for_tree_priority(tree_priority_);
   bool prioritize_low_res = tree_priority_ == SMOOTHNESS_TAKES_PRIORITY;
 
-  if (b_priority.resolution != a_priority.resolution) {
-    return (prioritize_low_res && b_priority.resolution == LOW_RESOLUTION) ||
-           (!prioritize_low_res && b_priority.resolution == HIGH_RESOLUTION) ||
-           (a_priority.resolution == NON_IDEAL_RESOLUTION);
+  // Now we have to return true iff b is higher priority than a.
+
+  // If the bin is the same but the resolution is not, then the order will be
+  // determined by whether we prioritize low res or not.
+  if (b_priority.priority_bin == a_priority.priority_bin &&
+      b_priority.resolution != a_priority.resolution) {
+    // Non ideal resolution should be sorted lower than other resolutions.
+    if (a_priority.resolution == NON_IDEAL_RESOLUTION)
+      return true;
+
+    if (b_priority.resolution == NON_IDEAL_RESOLUTION)
+      return false;
+
+    if (prioritize_low_res)
+      return b_priority.resolution == LOW_RESOLUTION;
+
+    return b_priority.resolution == HIGH_RESOLUTION;
   }
 
   return b_priority.IsHigherPriorityThan(a_priority);
 }
 
 TileManager::EvictionTileIterator::EvictionTileIterator()
     : comparator_(SAME_PRIORITY_FOR_BOTH_TREES) {}
 
 TileManager::EvictionTileIterator::EvictionTileIterator(
     TileManager* tile_manager,
@@ skipping 177 matching lines @@
   TRACE_EVENT0("cc", "TileManager::CheckIfReadyToActivate");
 
   rasterizer_->CheckForCompletedTasks();
   did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   if (IsReadyToActivate())
     client_->NotifyReadyToActivate();
 }
 
 }  // namespace cc