Allow ProxyService to share URLRequestContext with everything else.

net/proxy/proxy_service.cc

Index: net/proxy/proxy_service.cc
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index a81d3f66bc7547e22e813ff62ec94e9c0dd72e7d..a57557b58e25aab34ba9090c75442afeb27a64b1 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -456,6 +456,12 @@ class ProxyService::InitProxyResolver {
     return LOAD_STATE_RESOLVING_PROXY_FOR_URL;
   }
 
+  // This must be called before the HostResolver is torn down.
+  void OnShutdown() {
+    if (decider_)
+      decider_->OnShutdown();
+  }
+
   void set_quick_check_enabled(bool enabled) { quick_check_enabled_ = enabled; }
   bool quick_check_enabled() const { return quick_check_enabled_; }
 
@@ -1458,6 +1464,17 @@ void ProxyService::SetProxyScriptFetchers(
     ApplyProxyConfigIfAvailable();
 }
 
+void ProxyService::OnShutdown() {
+  // Order here does not matter for correctness. |init_proxy_resolver_| is first
+  // because shutting it down also cancels its requests using the fetcher.
+  if (init_proxy_resolver_)
+    init_proxy_resolver_->OnShutdown();
+  if (proxy_script_fetcher_)
+    proxy_script_fetcher_->OnShutdown();
+  if (dhcp_proxy_script_fetcher_)
+    dhcp_proxy_script_fetcher_->OnShutdown();
+}
+
 ProxyScriptFetcher* ProxyService::GetProxyScriptFetcher() const {
   DCHECK(CalledOnValidThread());
   return proxy_script_fetcher_.get();