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..3548e59316b603a8610632692da725f7b8ac1c15 100644
--- a/net/proxy/proxy_script_fetcher_impl.cc
+++ b/net/proxy/proxy_script_fetcher_impl.cc
@@ -123,6 +123,9 @@ int ProxyScriptFetcherImpl::Fetch(
   DCHECK(!callback.is_null());
   DCHECK(text);
 
+  if (!url_request_context_)
+    return ERR_CONTEXT_SHUT_DOWN;
+
   // Handle base-64 encoded data-urls that contain custom PAC scripts.
   if (url.SchemeIs("data")) {
     std::string mime_type;
@@ -138,8 +141,10 @@ 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 +155,11 @@ 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;
@@ -183,6 +190,15 @@ URLRequestContext* ProxyScriptFetcherImpl::GetRequestContext() const {
   return url_request_context_;
 }
 
+void ProxyScriptFetcherImpl::OnShutdown() {
+  url_request_context_ = nullptr;
+
+  if (cur_request_) {
+    result_code_ = ERR_CONTEXT_SHUT_DOWN;
+    FetchCompleted();
+  }
+}
+
 void ProxyScriptFetcherImpl::OnAuthRequired(URLRequest* request,
                                             AuthChallengeInfo* auth_info) {
   DCHECK_EQ(request, cur_request_.get());
@@ -341,7 +357,7 @@ void ProxyScriptFetcherImpl::OnTimeout(int id) {
 
   DCHECK(cur_request_.get());
   result_code_ = ERR_TIMED_OUT;
-  cur_request_->Cancel();
+  FetchCompleted();
 }
 
 }  // namespace net