Turn off computation of the interest rect in cc in synchronized paint mode.

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 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 "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/auto_reset.h"
@@ skipping 917 matching lines @@
   settings->setPluginsEnabled(prefs.plugins_enabled);
   settings->setDOMPasteAllowed(prefs.dom_paste_enabled);
   settings->setUsesEncodingDetector(prefs.uses_universal_detector);
   settings->setTextAreasAreResizable(prefs.text_areas_are_resizable);
   settings->setAllowScriptsToCloseWindows(prefs.allow_scripts_to_close_windows);
   settings->setDownloadableBinaryFontsEnabled(prefs.remote_fonts_enabled);
   settings->setJavaScriptCanAccessClipboard(
       prefs.javascript_can_access_clipboard);
   WebRuntimeFeatures::enableXSLT(prefs.xslt_enabled);
   WebRuntimeFeatures::enableSlimmingPaintV2(prefs.slimming_paint_v2_enabled);
+  WebRuntimeFeatures::enableBlinkSynchronizedPainting(
+    prefs.blink_synchronized_painting_enabled);
   settings->setXSSAuditorEnabled(prefs.xss_auditor_enabled);
   settings->setDNSPrefetchingEnabled(prefs.dns_prefetching_enabled);
   settings->setLocalStorageEnabled(prefs.local_storage_enabled);
   settings->setSyncXHRInDocumentsEnabled(prefs.sync_xhr_in_documents_enabled);
   WebRuntimeFeatures::enableDatabase(prefs.databases_enabled);
   settings->setOfflineWebApplicationCacheEnabled(
       prefs.application_cache_enabled);
   settings->setCaretBrowsingEnabled(prefs.caret_browsing_enabled);
   settings->setHyperlinkAuditingEnabled(prefs.hyperlink_auditing_enabled);
   settings->setCookieEnabled(prefs.cookie_enabled);
@@ skipping 2764 matching lines @@
   if (IsUseZoomForDSFEnabled()) {
     compositor_->SetPaintedDeviceScaleFactor(device_scale_factor_);
     webview()->setZoomFactorForDeviceScaleFactor(
         device_scale_factor_);
   } else {
     webview()->setDeviceScaleFactor(device_scale_factor_);
   }
 }
 
 }  // namespace content