Add the "virtual" keyword on method overrides that are missing it.

chrome/common/security_filter_peer.h

Index: chrome/common/security_filter_peer.h
diff --git a/chrome/common/security_filter_peer.h b/chrome/common/security_filter_peer.h
index 2559bf343f6441ef9a12ea61c9f21689a931a61f..e82f748297c472a1c984f2bc898f8f3b139474a4 100644
--- a/chrome/common/security_filter_peer.h
+++ b/chrome/common/security_filter_peer.h
@@ -110,10 +110,10 @@ class ReplaceContentPeer : public SecurityFilterPeer {
   virtual void OnReceivedResponse(
       const webkit_glue::ResourceResponseInfo& info,
       bool content_filtered);
-  void OnReceivedData(const char* data, int len);
-  void OnCompletedRequest(const URLRequestStatus& status,
-                          const std::string& security_info,
-                          const base::Time& completion_time);
+  virtual void OnReceivedData(const char* data, int len);
+  virtual void OnCompletedRequest(const URLRequestStatus& status,
+                                  const std::string& security_info,
+                                  const base::Time& completion_time);
 
  private:
   webkit_glue::ResourceResponseInfo response_info_;