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

webkit/glue/webpreferences.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/glue/webpreferences.h"
 
 #include <unicode/uchar.h>
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 77 matching lines @@
       accelerated_filters_enabled(false),
       accelerated_plugins_enabled(false),
       memory_info_enabled(false),
       interactive_form_validation_enabled(true),
       fullscreen_enabled(false),
       allow_displaying_insecure_content(true),
       allow_running_insecure_content(false),
       should_print_backgrounds(false),
       enable_scroll_animator(false),
       hixie76_websocket_protocol_enabled(false),
-      visual_word_movement_enabled(false) {
+      visual_word_movement_enabled(false),
+      per_tile_drawing_enabled(false) {
 }
 
 WebPreferences::~WebPreferences() {
 }
 
 namespace {
 
 void setStandardFontFamilyWrapper(WebSettings* settings,
                                   const string16& font,
                                   UScriptCode script) {
@@ skipping 212 matching lines @@
 
   settings->setFullScreenEnabled(fullscreen_enabled);
   settings->setAllowDisplayOfInsecureContent(allow_displaying_insecure_content);
   settings->setAllowRunningOfInsecureContent(allow_running_insecure_content);
   settings->setShouldPrintBackgrounds(should_print_backgrounds);
   settings->setEnableScrollAnimator(enable_scroll_animator);
   settings->setHixie76WebSocketProtocolEnabled(
       hixie76_websocket_protocol_enabled);
   settings->setVisualWordMovementEnabled(visual_word_movement_enabled);
 
+  // Enable per-tile drawing if requested on the command line.
+  settings->setPerTileDrawingEnabled(per_tile_drawing_enabled);
+
   WebNetworkStateNotifier::setOnLine(is_online);
 }