Massively simplify the NetworkChangeNotifier infrastructure:...

net/base/host_resolver.h

Index: net/base/host_resolver.h
===================================================================
--- net/base/host_resolver.h	(revision 50775)
+++ net/base/host_resolver.h	(working copy)
@@ -21,7 +21,6 @@
 class BoundNetLog;
 class HostCache;
 class HostResolverImpl;
-class NetworkChangeNotifier;
 
 // This class represents the task of resolving hostnames (or IP address
 // literal) to an AddressList object.
@@ -236,10 +235,7 @@
 // Creates a HostResolver implementation that queries the underlying system.
 // (Except if a unit-test has changed the global HostResolverProc using
 // ScopedHostResolverProc to intercept requests to the system).
-// |network_change_notifier| must outlive HostResolver.  It can optionally be
-// NULL, in which case HostResolver will not respond to network changes.
-HostResolver* CreateSystemHostResolver(
-    NetworkChangeNotifier* network_change_notifier);
+HostResolver* CreateSystemHostResolver();
 
 }  // namespace net