Add metrics for DHCP WPAD feature.

net/proxy/dhcp_proxy_script_fetcher_win.h

Index: net/proxy/dhcp_proxy_script_fetcher_win.h
diff --git a/net/proxy/dhcp_proxy_script_fetcher_win.h b/net/proxy/dhcp_proxy_script_fetcher_win.h
index 3783971c8c0188243a0852a49df04fbe01db75a6..06e8a4b4e67424edaf1afad8571ad05b9f0cca84 100644
--- a/net/proxy/dhcp_proxy_script_fetcher_win.h
+++ b/net/proxy/dhcp_proxy_script_fetcher_win.h
@@ -12,6 +12,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/threading/non_thread_safe.h"
+#include "base/time.h"
 #include "base/timer.h"
 #include "net/proxy/dhcp_proxy_script_fetcher.h"
 
@@ -44,6 +45,7 @@ class DhcpProxyScriptFetcherWin
 
  protected:
   // Event/state transition handlers
+  void CancelImpl(bool user_initiated);
   void OnFetcherDone(int result);
   void OnWaitTimer();
   void TransitionToDone();
@@ -113,6 +115,9 @@ class DhcpProxyScriptFetcherWin
 
   base::OneShotTimer<DhcpProxyScriptFetcherWin> wait_timer_;
 
+  // Time |Fetch()| was last called, 0 if never.
+  base::TimeTicks fetch_start_time_;
+
   scoped_refptr<URLRequestContext> url_request_context_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(DhcpProxyScriptFetcherWin);