Allow ProxyService to share URLRequestContext with everything else.

net/proxy/proxy_script_fetcher_impl.cc

Index: net/proxy/proxy_script_fetcher_impl.cc
diff --git a/net/proxy/proxy_script_fetcher_impl.cc b/net/proxy/proxy_script_fetcher_impl.cc
index d78c9feb65a5df03252977a2594e24f285fd4cc1..f6395efb2c805c1348c3313d226175d6d09a238b 100644
--- a/net/proxy/proxy_script_fetcher_impl.cc
+++ b/net/proxy/proxy_script_fetcher_impl.cc
@@ -138,8 +138,10 @@ int ProxyScriptFetcherImpl::Fetch(
   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,
@@ -150,9 +152,11 @@ int ProxyScriptFetcherImpl::Fetch(
   // 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;