Allow the tiling of theme background images on the NTP....

chrome/browser/dom_ui/dom_ui_theme_source.h

Index: chrome/browser/dom_ui/dom_ui_theme_source.h
===================================================================
--- chrome/browser/dom_ui/dom_ui_theme_source.h	(revision 20990)
+++ chrome/browser/dom_ui/dom_ui_theme_source.h	(working copy)
@@ -35,6 +35,10 @@
   // states when the bar is attached or detached.
   std::string GetNewTabBackgroundCSS(bool bar_attached);
 
+  // How the background image on the new tab page should be tiled (see tiling
+  // masks in browser_theme_provider.h).
+  std::string GetNewTabBackgroundTilingCSS();
+
   Profile* profile_;
   DISALLOW_COPY_AND_ASSIGN(DOMUIThemeSource);
 };