cc: Change max_tiles_for_interest_rect to be screen pixels padding.

cc/tiles/picture_layer_tiling_set_unittest.cc

Index: cc/tiles/picture_layer_tiling_set_unittest.cc
diff --git a/cc/tiles/picture_layer_tiling_set_unittest.cc b/cc/tiles/picture_layer_tiling_set_unittest.cc
index e7593cde80b58609000e9882b28061aea3ff3788..d26615e5f59cea46035d5d2fd9306bc56fe75b27 100644
--- a/cc/tiles/picture_layer_tiling_set_unittest.cc
+++ b/cc/tiles/picture_layer_tiling_set_unittest.cc
@@ -25,7 +25,7 @@ scoped_ptr<PictureLayerTilingSet> CreateTilingSet(
     PictureLayerTilingClient* client) {
   LayerTreeSettings defaults;
   return PictureLayerTilingSet::Create(
-      ACTIVE_TREE, client, defaults.max_tiles_for_interest_area,
+      ACTIVE_TREE, client, defaults.tiling_interest_area_padding,
       defaults.skewport_target_time_in_seconds,
       defaults.skewport_extrapolation_limit_in_content_pixels);
 }