mojo: Make InterfacePtr<> testable in if() statements without .get().

mojo/shell/dynamic_service_loader.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 "mojo/shell/dynamic_service_loader.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 149 matching lines @@
   if (url.SchemeIs("mojo")) {
     resolved_url = context_->mojo_url_resolver()->Resolve(url);
   } else {
     resolved_url = url;
   }
 
   Loader* loader;
   if (resolved_url.SchemeIsFile()) {
     loader = new LocalLoader(runner.Pass());
   } else {
-    if (!network_service_.get()) {
+    if (!network_service_) {
       context_->service_manager()->ConnectToService(
           GURL("mojo:mojo_network_service"),
           &network_service_);
     }
     loader = new NetworkLoader(runner.Pass(), network_service_.get());
   }
   loader->Start(resolved_url, shell_handle.Pass(), context_);
 }
 
 void DynamicServiceLoader::OnServiceError(ServiceManager* manager,
                                           const GURL& url) {
   // TODO(darin): What should we do about service errors? This implies that
   // the app closed its handle to the service manager. Maybe we don't care?
 }
 
 }  // namespace shell
 }  // namespace mojo