Merge 138112 - NTP: Prevent tab sync icons from being cached.

chrome/browser/ui/webui/chrome_url_data_manager.h

Index: chrome/browser/ui/webui/chrome_url_data_manager.h
===================================================================
--- chrome/browser/ui/webui/chrome_url_data_manager.h	(revision 140618)
+++ chrome/browser/ui/webui/chrome_url_data_manager.h	(working copy)
@@ -107,6 +107,9 @@
     // TODO: nuke this and convert all callers to not replace.
     virtual bool ShouldReplaceExistingSource() const;
 
+    // Returns true if responses from this DataSource can be cached.
+    virtual bool AllowCaching() const { return true; }
+
     static void SetFontAndTextDirection(
         base::DictionaryValue* localized_strings);