Add a constraint on how many requests can be outstanding for any given render (browser-side).

net/url_request/url_request.cc

 // Copyright (c) 2006-2008 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/basictypes.h"
 #include "base/message_loop.h"
 #include "base/process_util.h"
 #include "base/singleton.h"
@@ skipping 216 matching lines @@
   job_->Start();
 }
 
 void URLRequest::Cancel() {
   CancelWithError(net::ERR_ABORTED);
 }
 
 void URLRequest::CancelWithError(int os_error) {
   DCHECK(os_error < 0);
 
-  // There's nothing to do if we are not waiting on a Job.
-  if (!is_pending_ || !job_)
-    return;
-
   // If the URL request already has an error status, then canceling is a no-op.
   // Plus, we don't want to change the error status once it has been set.
   if (status_.is_success()) {
     status_.set_status(URLRequestStatus::CANCELED);
     status_.set_os_error(os_error);
   }
 
+  // There's nothing to do if we are not waiting on a Job.
+  if (!is_pending_ || !job_)
+    return;
+
   job_->Kill();
 
   // The Job will call our NotifyDone method asynchronously.  This is done so
   // that the Delegate implementation can call Cancel without having to worry
   // about being called recursively.
 }
 
 bool URLRequest::Read(net::IOBuffer* dest, int dest_size, int *bytes_read) {
   DCHECK(job_);
   DCHECK(bytes_read);
@@ skipping 85 matching lines @@
     // NOTE: Even though RFC 2616 says to preserve the request method when
     // following a 302 redirect, normal browsers don't do that.  Instead, they
     // all convert a POST into a GET in response to a 302 and so shall we.  For
     // 307 redirects, browsers preserve the method.  The RFC says to prompt the
     // user to confirm the generation of a new POST request, but IE omits this
     // prompt and so shall we.
     strip_post_specific_headers = method_ == "POST";
     method_ = "GET";
   }
   url_ = location;
-  upload_ = 0;
+  upload_ = NULL;
   status_ = URLRequestStatus();
   --redirect_limit_;
 
   if (strip_post_specific_headers) {
     // If being switched from POST to GET, must remove headers that were
     // specific to the POST and don't have meaning in GET. For example
     // the inclusion of a multipart Content-Type header in GET can cause
     // problems with some servers:
     // http://code.google.com/p/chromium/issues/detail?id=843
     //
@@ skipping 13 matching lines @@
   return net::OK;
 }
 
 int64 URLRequest::GetExpectedContentSize() const {
   int64 expected_content_size = -1;
   if (job_)
     expected_content_size = job_->expected_content_size();
 
   return expected_content_size;
 }