Add the UMA recording recall of URLRequests preconnected.

chrome/browser/net/connect_interceptor.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_NET_CONNECT_INTERCEPTOR_H_
 #define CHROME_BROWSER_NET_CONNECT_INTERCEPTOR_H_
 
 #include "base/containers/mru_cache.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 15 matching lines @@
 class ConnectInterceptor {
  public:
   // Construction includes registration as an URL.
   explicit ConnectInterceptor(Predictor* predictor);
   // Destruction includes unregistering.
   virtual ~ConnectInterceptor();
 
   // Learn about referrers, and optionally preconnect based on history.
   void WitnessURLRequest(net::URLRequest* request) const;
 
+  void WitnessPreconnect(const GURL& url);
+
  private:
   // Provide access to local class TimedCache for testing.
   FRIEND_TEST_ALL_PREFIXES(ConnectInterceptorTest, TimedCacheRecall);
   FRIEND_TEST_ALL_PREFIXES(ConnectInterceptorTest, TimedCacheEviction);
 
   // Define a LRU cache that recalls all navigations within the last N seconds.
   // When we learn about subresources to possibly preconnect to, it would be a
   // waste to preconnect when the original navigation was too long ago.  Any
   // connected, but unused TCP/IP connection, will generally be reset by the
   // server if it is not used quickly (i.e., GET or POST is sent).
@@ skipping 18 matching lines @@
     // URLRequestJob functions. It is mutable because it tracks the urls and
     // caches them.
     mutable UrlMruTimedCache mru_cache_;
 
     // The longest time an entry can persist in the cache, and still be found.
     const base::TimeDelta max_duration_;
 
     DISALLOW_COPY_AND_ASSIGN(TimedCache);
   };
   TimedCache timed_cache_;
+  TimedCache recent_preconnects_;
   Predictor* const predictor_;
 
   DISALLOW_COPY_AND_ASSIGN(ConnectInterceptor);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_CONNECT_INTERCEPTOR_H_