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..8ccc64885ffef7624f255635fdf701af93ec8334 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -530,8 +530,12 @@ TileManager::FreeTileResourcesWithLowerPriorityUntilUsageIsWithinLimit(
       break;
 
     Tile* tile = eviction_priority_queue->Top();
-    if (!other_priority.IsHigherPriorityThan(tile->combined_priority()))
+    const TilePriority& current_priority = tile->combined_priority();
+    if (!tile->is_occluded_combined() &&
+        (current_priority.resolution != NON_IDEAL_RESOLUTION) &&

[vmiura, 2015/02/12 22:18:41]

What are the implications of these additional checks?

[vmpstr, 2015/02/12 23:38:19]

This is just making us be able to have more memory for rasterization. Without
this a tile of a non ideal scale can block rasterization of a high res tile for
instance, because we don't have memory... This is kind of an optional change,
but I think it makes it a bit more robust. Let me know if you prefer I did this
separately (or didn't do it at all :) ) (I also changed the condition a bit and
added comments).

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