Add the UMA recording recall of URLRequests preconnected.

net/base/network_delegate.h

 // Copyright (c) 2012 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 NET_BASE_NETWORK_DELEGATE_H_
 #define NET_BASE_NETWORK_DELEGATE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 47 matching lines @@
     REQUEST_WAIT_STATE_NETWORK_FINISH,
     REQUEST_WAIT_STATE_RESET
   };
 
   virtual ~NetworkDelegate() {}
 
   // Notification interface called by the network stack. Note that these
   // functions mostly forward to the private virtuals. They also add some sanity
   // checking on parameters. See the corresponding virtuals for explanations of
   // the methods and their arguments.
+  void NotifyBeforePreconnect(const GURL& url);

[mmenke, 2013/05/22 17:58:43]

This is an interface for the network stack, in net/, to communicate with the
consumer (The browser).  We shouldn't have functions here just for non-src/net
functions to call.

[kouhei (in TOK), 2013/05/23 07:31:13]

ok.

   int NotifyBeforeURLRequest(URLRequest* request,
                              const CompletionCallback& callback,
                              GURL* new_url);
   int NotifyBeforeSendHeaders(URLRequest* request,
                               const CompletionCallback& callback,
                               HttpRequestHeaders* headers);
   void NotifySendHeaders(URLRequest* request,
                          const HttpRequestHeaders& headers);
   int NotifyHeadersReceived(
       URLRequest* request,
@@ skipping 26 matching lines @@
                                       const CompletionCallback& callback);
 
   void NotifyRequestWaitStateChange(const URLRequest& request,
                                     RequestWaitState state);
 
  private:
   // This is the interface for subclasses of NetworkDelegate to implement. These
   // member functions will be called by the respective public notification
   // member function, which will perform basic sanity checking.
 
+  // Called before a preconnect is processed.
+  virtual void OnBeforePreconnect(const GURL& url) {}
+
   // Called before a request is sent. Allows the delegate to rewrite the URL
   // being fetched by modifying |new_url|. |callback| and |new_url| are valid
   // only until OnURLRequestDestroyed is called for this request. Returns a net
   // status code, generally either OK to continue with the request or
   // ERR_IO_PENDING if the result is not ready yet. A status code other than OK
   // and ERR_IO_PENDING will cancel the request and report the status code as
   // the reason.
   virtual int OnBeforeURLRequest(URLRequest* request,
                                  const CompletionCallback& callback,
                                  GURL* new_url) = 0;
@@ skipping 118 matching lines @@
   // action or a network action, or when that is no longer the case.
   // REQUEST_WAIT_STATE_RESET indicates for a given URLRequest
   // cancellation of any pending waits for this request.
   virtual void OnRequestWaitStateChange(const URLRequest& request,
                                         RequestWaitState state) = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NETWORK_DELEGATE_H_