Add a command-line switch --enable-per-tile-painting.

webkit/glue/webpreferences.h

Index: webkit/glue/webpreferences.h
diff --git a/webkit/glue/webpreferences.h b/webkit/glue/webpreferences.h
index a7cdfc12069980102c5058d1f2d5ad71b8b6da22..8c3f70fc57034028a6155f4f17643b0d3bfc656e 100644
--- a/webkit/glue/webpreferences.h
+++ b/webkit/glue/webpreferences.h
@@ -99,7 +99,7 @@ struct WEBKIT_GLUE_EXPORT WebPreferences {
   bool accelerated_layers_enabled;
   bool accelerated_video_enabled;
   bool accelerated_2d_canvas_enabled;
-  bool accelerated_drawing_enabled;
+  bool accelerated_painting_enabled;
   bool accelerated_filters_enabled;
   bool accelerated_plugins_enabled;
   bool memory_info_enabled;
@@ -111,6 +111,7 @@ struct WEBKIT_GLUE_EXPORT WebPreferences {
   bool enable_scroll_animator;
   bool hixie76_websocket_protocol_enabled;
   bool visual_word_movement_enabled;
+  bool per_tile_painting_enabled;
   // We try to keep the default values the same as the default values in
   // chrome, except for the cases where it would require lots of extra work for
   // the embedder to use the same default value.