Allows deferral of a URLRequest just before talking to the network, at

net/url_request/url_request.cc

Index: net/url_request/url_request.cc
diff --git a/net/url_request/url_request.cc b/net/url_request/url_request.cc
index ce267302ee1bd90116606062f2c7695ff537fd4d..54fd28d2058d6bb27577d8a441150a30f9f7e02f 100644
--- a/net/url_request/url_request.cc
+++ b/net/url_request/url_request.cc
@@ -198,6 +198,10 @@ void URLRequest::Delegate::OnSSLCertificateError(URLRequest* request,
   request->Cancel();
 }
 
+void URLRequest::Delegate::OnBeforeNetworkStart(URLRequest* request,
+                                                bool* defer) {
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // URLRequest
 
@@ -225,7 +229,8 @@ URLRequest::URLRequest(const GURL& url,
                                           base::Unretained(this))),
       has_notified_completion_(false),
       received_response_content_length_(0),
-      creation_time_(base::TimeTicks::Now()) {
+      creation_time_(base::TimeTicks::Now()),
+      notified_before_network_start_(false) {
   SIMPLE_STATS_COUNTER("URLRequestCount");
 
   // Sanity check out environment.
@@ -824,6 +829,24 @@ void URLRequest::NotifyReceivedRedirect(const GURL& location,
   }
 }
 
+void URLRequest::NotifyBeforeNetworkStart(bool* defer) {
+  if (delegate_ && !notified_before_network_start_) {
+    OnCallToDelegate();
+    delegate_->OnBeforeNetworkStart(this, defer);
+    if (!*defer)
+      OnCallToDelegateComplete();
+    notified_before_network_start_ = true;
+  }
+}
+
+void URLRequest::ResumeNetworkStart() {
+  DCHECK(job_);
+  DCHECK(notified_before_network_start_);
+
+  OnCallToDelegateComplete();
+  job_->ResumeNetworkStart();
+}
+
 void URLRequest::NotifyResponseStarted() {
   int net_error = OK;
   if (!status_.is_success())