NTP: Prevent tab sync icons from being cached.

chrome/browser/ui/webui/session_favicon_source.h

Index: chrome/browser/ui/webui/session_favicon_source.h
diff --git a/chrome/browser/ui/webui/session_favicon_source.h b/chrome/browser/ui/webui/session_favicon_source.h
index 33ec6d29e61e282ea78046246ade395bea727ef2..889a9ee37343461981297def041fc6a5d24b7969 100644
--- a/chrome/browser/ui/webui/session_favicon_source.h
+++ b/chrome/browser/ui/webui/session_favicon_source.h
@@ -19,15 +19,13 @@ class SessionFaviconSource : public FaviconSource {
  public:
   explicit SessionFaviconSource(Profile* profile);
 
-  // Called when the network layer has requested a resource underneath
-  // the path we registered.
+  // FaviconSource implementation.
   virtual void StartDataRequest(const std::string& path,
                                 bool is_incognito,
                                 int request_id) OVERRIDE;
-
   virtual std::string GetMimeType(const std::string&) const OVERRIDE;
-
   virtual bool ShouldReplaceExistingSource() const OVERRIDE;
+  virtual bool AllowCaching() const OVERRIDE;
 
  protected:
   virtual ~SessionFaviconSource();