Refactor Blink's ServiceConnector and add ability to mock in layout tests

third_party/WebKit/Source/platform/ServiceConnector.h

-// Copyright 2016 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.
-
-#ifndef ServiceConnector_h
-#define ServiceConnector_h
-
-#include "mojo/public/cpp/bindings/binding.h"
-#include "public/platform/Platform.h"
-#include "services/service_manager/public/interfaces/connector.mojom-blink.h"
-#include "wtf/StdLibExtras.h"
-
-namespace blink {
-
-// ServiceConnector supports connecting to Mojo services by name.
-class ServiceConnector {
- public:
-  static ServiceConnector& instance() {
-    DEFINE_STATIC_LOCAL(ServiceConnector, instance, ());
-    return instance;
-  }
-
-  template <typename Interface>
-  void connectToInterface(const char* serviceName,
-                          mojo::InterfaceRequest<Interface> request) {
-    if (!m_connector.is_bound()) {
-      Platform::current()->bindServiceConnector(
-          mojo::MakeRequest(&m_connector).PassMessagePipe());
-    }
-
-    if (m_connector.encountered_error())
-      return;
-
-    service_manager::mojom::blink::IdentityPtr remoteIdentity(
-        service_manager::mojom::blink::Identity::New());
-    remoteIdentity->name = serviceName;
-    remoteIdentity->user_id = service_manager::mojom::blink::kInheritUserID;
-    remoteIdentity->instance = "";
-
-    service_manager::mojom::blink::InterfaceProviderPtr remoteInterfaces;
-    m_connector->Connect(std::move(remoteIdentity),
-                         MakeRequest(&remoteInterfaces),
-                         base::Bind(&ServiceConnector::onConnectionCompleted));
-
-    remoteInterfaces->GetInterface(Interface::Name_, request.PassMessagePipe());
-  }
-
- private:
-  ServiceConnector() {}
-
-  static void onConnectionCompleted(
-      service_manager::mojom::ConnectResult result,
-      const WTF::String& targetUserID) {}
-
-  service_manager::mojom::blink::ConnectorPtr m_connector;
-};
-
-}  // namespace blink
-
-#endif  // ServiceConnector_h