Remove some calls to URLRequestContext::network_delegate().

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 5d3e26b47fedbce7b639f88bab9879b91e1a9667..f14693b56a7afeba0e55914d5aa436c19effa0af 100644
--- a/net/url_request/url_request.cc
+++ b/net/url_request/url_request.cc
@@ -454,6 +454,10 @@ void URLRequest::set_delegate(Delegate* delegate) {
   delegate_ = delegate;
 }
 
+bool URLRequest::CanThrottle() const {
+  return !network_delegate_ || network_delegate_->CanThrottleRequest(*this);
+}
+
 void URLRequest::Start() {
   DCHECK_EQ(network_delegate_, context_->network_delegate());
 
@@ -820,6 +824,10 @@ const URLRequestContext* URLRequest::context() const {
   return context_;
 }
 
+NetworkDelegate* URLRequest::network_delegate() const {
+  return network_delegate_;
+}
+
 int64 URLRequest::GetExpectedContentSize() const {
   int64 expected_content_size = -1;
   if (job_)