cc: Switch eviction iterators to consider combined priority.

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 94b6332a9aa4229bcfaa1b90831beba679a39416..2f5de410eef19a446612b8d489339227183609ab 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -530,8 +530,19 @@ TileManager::FreeTileResourcesWithLowerPriorityUntilUsageIsWithinLimit(
       break;
 
     Tile* tile = eviction_priority_queue->Top();
-    if (!other_priority.IsHigherPriorityThan(tile->combined_priority()))
+    const TilePriority& eviction_priority = tile->combined_priority();
+
+    // If eviction tile is strictly higher priority, then we can't evict.
+    if (eviction_priority.IsHigherPriorityThan(other_priority))
+      break;
+
+    // If there's a tie in priority, prefer to the keep the eviction tile
+    // unless it's non ideal resolution or is occluded.
+    if (!tile->is_occluded_combined() &&
+        (eviction_priority.resolution != NON_IDEAL_RESOLUTION) &&

[danakj, 2015/02/12 23:48:46]

I think you should do this separately with a test to demonstrate it.

[vmpstr, 2015/02/12 23:52:34]

OK. Removed from this CL.

+        !other_priority.IsHigherPriorityThan(tile->combined_priority())) {
       break;
+    }
 
     *usage -= MemoryUsage::FromTile(tile);
     FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);