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

net/url_request/url_request.cc

 // 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.
 
 #include "net/url_request/url_request.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
@@ skipping 132 matching lines @@
       load_flags_(LOAD_NORMAL),
       delegate_(delegate),
       is_pending_(false),
       redirect_limit_(kMaxRedirects),
       final_upload_progress_(0),
       priority_(LOWEST),
       identifier_(GenerateURLRequestIdentifier()),
       blocked_on_delegate_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(
           before_request_callback_(this, &URLRequest::BeforeRequestComplete)),
-      has_notified_completion_(false) {
+      has_notified_completion_(false),
+      start_time_(base::TimeTicks::Now()) {
   SIMPLE_STATS_COUNTER("URLRequestCount");
 
   // Sanity check out environment.
   DCHECK(MessageLoop::current()) <<
       "The current MessageLoop must exist";
   DCHECK_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type()) <<
       "The current MessageLoop must be TYPE_IO";
 }
 
 URLRequest::~URLRequest() {
@@ skipping 241 matching lines @@
   }
 
   return ret;
 }
 
 void URLRequest::set_delegate(Delegate* delegate) {
   delegate_ = delegate;
 }
 
 void URLRequest::Start() {
   response_info_.request_time = Time::Now();

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

Since URLRequest has a Start() method, setting the
start_time_ member in the constructor rather than in the
Start() method is confusing.  Perhaps the member should be
named create_time_ instead?

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

Done.

 
   // Only notify the delegate for the initial request.
   if (context_ && context_->network_delegate()) {
     int error = context_->network_delegate()->NotifyBeforeURLRequest(
         this, &before_request_callback_, &delegate_redirect_url_);
     if (error != net::OK) {
       if (error == net::ERR_IO_PENDING) {
         // Paused on the delegate, will invoke |before_request_callback_| later.
         SetBlockedOnDelegate();
       } else {
@@ skipping 466 matching lines @@
 
 void URLRequest::SetUnblockedOnDelegate() {
   if (!blocked_on_delegate_)
     return;
   blocked_on_delegate_ = false;
   load_state_param_.clear();
   net_log_.EndEvent(NetLog::TYPE_URL_REQUEST_BLOCKED_ON_DELEGATE, NULL);
 }
 
 }  // namespace net