cc: Remove tile sharing from tilings.

cc/resources/raster_tile_priority_queue_all.cc

Index: cc/resources/raster_tile_priority_queue_all.cc
diff --git a/cc/resources/raster_tile_priority_queue_all.cc b/cc/resources/raster_tile_priority_queue_all.cc
index 9baa9b32de7177e67738a675a78dda8f1cf65779..7b0eca3864354d45e7ae3227b1ec72674af90e7b 100644
--- a/cc/resources/raster_tile_priority_queue_all.cc
+++ b/cc/resources/raster_tile_priority_queue_all.cc
@@ -105,8 +105,25 @@ WhichTree HigherPriorityTree(TreePriority tree_priority,
       }
       return ACTIVE_TREE;
     }
-    case NEW_CONTENT_TAKES_PRIORITY:
+    case NEW_CONTENT_TAKES_PRIORITY: {
+      const Tile* active_tile = shared_tile ? shared_tile : active_queue->Top();
+      const Tile* pending_tile =
+          shared_tile ? shared_tile : pending_queue->Top();
+
+      const TilePriority& active_priority = active_tile->priority(ACTIVE_TREE);
+      const TilePriority& pending_priority =
+          pending_tile->priority(PENDING_TREE);
+
+      // If we're down to soon bin tiles on the pending tree, process the
+      // active tree to allow tiles required for activation to be initialized
+      // when memory policy only allows prepaint. Note that active required for
+      // activation tiles might come from either now or soon bins.
+      if (pending_priority.priority_bin >= TilePriority::SOON &&
+          active_priority.priority_bin <= TilePriority::SOON) {
+        return ACTIVE_TREE;
+      }
       return PENDING_TREE;
+    }
     case SAME_PRIORITY_FOR_BOTH_TREES: {
       const Tile* active_tile = shared_tile ? shared_tile : active_queue->Top();
       const Tile* pending_tile =