Allow ProxyService to share URLRequestContext with everything else.

net/proxy/proxy_script_fetcher_impl.cc

 // Copyright (c) 2012 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/proxy/proxy_script_fetcher_impl.h"
 
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
@@ skipping 120 matching lines @@
     if (!DataURL::Parse(url, &mime_type, &charset, &data))
       return ERR_FAILED;
 
     ConvertResponseToUTF16(charset, data, text);
     return OK;
   }
 
   DCHECK(fetch_start_time_.is_null());
   fetch_start_time_ = base::TimeTicks::Now();
 
+  // Use highest priority, so if socket pools are being used for other types of
+  // requests, PAC requests are aren't blocked on them.
   cur_request_ =
-      url_request_context_->CreateRequest(url, DEFAULT_PRIORITY, this);
+      url_request_context_->CreateRequest(url, MAXIMUM_PRIORITY, this);
   cur_request_->set_method("GET");
 
   // Make sure that the PAC script is downloaded using a direct connection,
   // to avoid circular dependencies (fetching is a part of proxy resolution).
   // Also disable the use of the disk cache. The cache is disabled so that if
   // the user switches networks we don't potentially use the cached response
   // from old network when we should in fact be re-fetching on the new network.
   // If the PAC script is hosted on an HTTPS server we bypass revocation
   // checking in order to avoid a circular dependency when attempting to fetch
   // the OCSP response or CRL. We could make the revocation check go direct but
-  // the proxy might be the only way to the outside world.
+  // the proxy might be the only way to the outside world.  IGNORE_LIMITS is
+  // used to avoid blocking proxy resolution on other network requests.
   cur_request_->SetLoadFlags(LOAD_BYPASS_PROXY | LOAD_DISABLE_CACHE |
-                             LOAD_DISABLE_CERT_REVOCATION_CHECKING);
+                             LOAD_DISABLE_CERT_REVOCATION_CHECKING |
+                             LOAD_IGNORE_LIMITS);
 
   // Save the caller's info for notification on completion.
   callback_ = callback;
   result_text_ = text;
 
   bytes_read_so_far_.clear();
 
   // Post a task to timeout this request if it takes too long.
   cur_request_id_ = ++next_id_;
 
@@ skipping 172 matching lines @@
   // is still applicable.
   if (cur_request_id_ != id)
     return;
 
   DCHECK(cur_request_.get());
   result_code_ = ERR_TIMED_OUT;
   cur_request_->Cancel();
 }
 
 }  // namespace net