Use a monotonic clock (TimeTicks) to report network times to WebCore.

net/url_request/url_request.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 NET_URL_REQUEST_URL_REQUEST_H_
 #define NET_URL_REQUEST_URL_REQUEST_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 32 matching lines @@
 // Temporary layering violation to allow existing users of a deprecated
 // interface.
 namespace appcache {
 class AppCacheInterceptor;
 class AppCacheRequestHandlerTest;
 class AppCacheURLRequestJobTest;
 }
 
 namespace base {
 class Time;
+class TimeTicks;

[wtc, 2011/12/06 21:00:53]

Since the URLRequest class contains a base::TimeTicks member,
it seems that a forward declaration of base::TimeTicks is
not enough.  I suspect that "base/time.h" is already included
by one of the headers above.

[James Simonsen, 2011/12/10 00:21:47]

Done.

 }  // namespace base
 
 // Temporary layering violation to allow existing users of a deprecated
 // interface.
 namespace fileapi {
 class FileSystemDirURLRequestJobTest;
 class FileSystemOperationWriteTest;
 class FileSystemURLRequestJobTest;
 class FileWriterDelegateTest;
 }
@@ skipping 390 matching lines @@
   void GetResponseHeaderByName(const std::string& name, std::string* value);
 
   // Get all response headers, \n-delimited and \n\0-terminated.  This includes
   // the response status line.  Restrictions on GetResponseHeaders apply.
   void GetAllResponseHeaders(std::string* headers);
 
   // The time at which the returned response was requested.  For cached
   // responses, this is the last time the cache entry was validated.
   const base::Time& request_time() const {
     return response_info_.request_time;
   }

[wtc, 2011/12/06 21:00:53]

I highly recommend that you declare the new start_time()
method here, right next to the closely related and easily
confused request_time() method.

It may make sense to name the method start_time_ticks()
to give a hint of the return type.

[James Simonsen, 2011/12/10 00:21:47]

Done.

 
   // The time at which the returned response was generated.  For cached
   // responses, this is the last time the cache entry was validated.
   const base::Time& response_time() const {
     return response_info_.response_time;
   }
 
   // Indicate if this response was fetched from disk cache.
   bool was_cached() const { return response_info_.was_cached; }
 
@@ skipping 151 matching lines @@
   void set_priority(RequestPriority priority) {
     DCHECK_GE(priority, HIGHEST);
     DCHECK_LT(priority, NUM_PRIORITIES);
     priority_ = priority;
   }
 
   // This method is intended only for unit tests, but it is being used by
   // unit tests outside of net :(.
   URLRequestJob* job() { return job_; }
 
+  base::TimeTicks start_time() const { return start_time_; }
+
  protected:
   // Allow the URLRequestJob class to control the is_pending() flag.
   void set_is_pending(bool value) { is_pending_ = value; }
 
   // Allow the URLRequestJob class to set our status too
   void set_status(const URLRequestStatus& value) { status_ = value; }
 
   // Allow the URLRequestJob to redirect this request.  Returns OK if
   // successful, otherwise an error code is returned.
   int Redirect(const GURL& location, int http_status_code);
@@ skipping 162 matching lines @@
   // TODO(battre): Remove this. http://crbug.com/89049
   bool has_notified_completion_;
 
   // Authentication data used by the NetworkDelegate for this request,
   // if one is present. |auth_credentials_| may be filled in when calling
   // |NotifyAuthRequired| on the NetworkDelegate. |auth_info_| holds
   // the authentication challenge being handled by |NotifyAuthRequired|.
   AuthCredentials auth_credentials_;
   scoped_refptr<AuthChallengeInfo> auth_info_;
 
+  // When this request was created.

[wtc, 2011/12/06 21:00:53]

Move or copy this comment to the start_time() method.

[James Simonsen, 2011/12/10 00:21:47]

Done.

+  base::TimeTicks start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(URLRequest);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_H_