Remove last uses of InterfaceImpl<> in Sky C++ code

sky/viewer/content_handler_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sky/viewer/content_handler_impl.h"
 
 #include "base/bind.h"
 #include "mojo/public/cpp/application/connect.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/public/cpp/utility/run_loop.h"
@@ skipping 59 matching lines @@
                      shell_.get());
   }
 
   mojo::String url_;
   mojo::StrongBinding<mojo::Application> binding_;
   mojo::ShellPtr shell_;
   mojo::NetworkServicePtr network_service_;
   mojo::URLResponsePtr initial_response_;
 };
 
-ContentHandlerImpl::ContentHandlerImpl() {
+ContentHandlerImpl::ContentHandlerImpl(
+    mojo::InterfaceRequest<mojo::ContentHandler> request)
+    : binding_(this, request.Pass()) {
 }
 
 ContentHandlerImpl::~ContentHandlerImpl() {
 }
 
 void ContentHandlerImpl::StartApplication(
     mojo::InterfaceRequest<mojo::Application> application,
     mojo::URLResponsePtr response) {
   new SkyApplication(application.Pass(), response.Pass());
 }
 
 }  // namespace sky