Don't delay creation of system URLRequestContext until first use

components/proxy_config/pref_proxy_config_tracker_impl.h

Index: components/proxy_config/pref_proxy_config_tracker_impl.h
diff --git a/components/proxy_config/pref_proxy_config_tracker_impl.h b/components/proxy_config/pref_proxy_config_tracker_impl.h
index ec42a7922179569ea2f3d8d05ecacf64b131941a..0c1d537194b222d4b313ee6e9e555b9d73ea0c1c 100644
--- a/components/proxy_config/pref_proxy_config_tracker_impl.h
+++ b/components/proxy_config/pref_proxy_config_tracker_impl.h
@@ -37,9 +37,9 @@ class ProxyConfigServiceImpl : public net::ProxyConfigService,
                                public net::ProxyConfigService::Observer {
  public:
   // Takes ownership of the passed |base_service|.
-  // GetLatestProxyConfig returns ConfigAvailability::CONFIG_PENDING until
-  // UpdateProxyConfig has been called.
-  explicit ProxyConfigServiceImpl(net::ProxyConfigService* base_service);
+  explicit ProxyConfigServiceImpl(net::ProxyConfigService* base_service,
+                                  ProxyPrefs::ConfigState initial_config_state,
+                                  const net::ProxyConfig& initial_config);

[stevenjb, 2017/05/10 18:46:16]

No longer explicit
s/initial_config/initial_pref_config/

[mmenke, 2017/05/10 18:59:20]

Done.

   ~ProxyConfigServiceImpl() override;
 
   // ProxyConfigService implementation:
@@ -71,10 +71,6 @@ class ProxyConfigServiceImpl : public net::ProxyConfigService,
   // Configuration as defined by prefs.
   net::ProxyConfig pref_config_;
 
-  // Flag that indicates that a PrefProxyConfigTracker needs to inform us
-  // about a proxy configuration before we may return any configuration.
-  bool pref_config_read_pending_;
-
   // Indicates whether the base service registration is done.
   bool registered_observer_;