Split ProxyResolverV8Tracing into an implementation and a wrapper.

net/proxy/mojo_proxy_resolver_impl.h

Index: net/proxy/mojo_proxy_resolver_impl.h
diff --git a/net/proxy/mojo_proxy_resolver_impl.h b/net/proxy/mojo_proxy_resolver_impl.h
index a99c6a4aa8b7cd19c1313e71199266fbcebd1821..2d801c8c4389b4cf13ee94c19cb7f4feaee83083 100644
--- a/net/proxy/mojo_proxy_resolver_impl.h
+++ b/net/proxy/mojo_proxy_resolver_impl.h
@@ -18,11 +18,7 @@ namespace net {
 
 class MojoProxyResolverImpl : public interfaces::ProxyResolver {
  public:
-  MojoProxyResolverImpl(
-      scoped_ptr<net::ProxyResolver> resolver,
-      const base::Callback<
-          void(const net::ProxyResolver::LoadStateChangedCallback&)>&
-          load_state_change_callback_setter);
+  explicit MojoProxyResolverImpl(scoped_ptr<net::ProxyResolver> resolver);
 
   ~MojoProxyResolverImpl() override;
 
@@ -36,10 +32,6 @@ class MojoProxyResolverImpl : public interfaces::ProxyResolver {
 
   void DeleteJob(Job* job);
 
-  // Invoked when the LoadState of a request changes.
-  void LoadStateChanged(net::ProxyResolver::RequestHandle handle,
-                        LoadState load_state);
-
   scoped_ptr<net::ProxyResolver> resolver_;
   std::set<Job*> resolve_jobs_;
   std::map<net::ProxyResolver::RequestHandle, Job*> request_handle_to_job_;