Add a Javascript wrapper around ServiceRegistry and expose it to WebUI.

chrome/browser/ui/webui/mojo_web_ui_controller.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_MOJO_WEB_UI_CONTROLLER_H_
 #define CHROME_BROWSER_UI_WEBUI_MOJO_WEB_UI_CONTROLLER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "chrome/browser/ui/webui/mojo_web_ui_handler.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_ui_controller.h"
+#include "content/public/common/service_registry.h"
 #include "mojo/public/cpp/system/core.h"
 
 class MojoWebUIHandler;
 
 namespace content {
 class WebUIDataSource;
 }
 
+class MojoWebUIControllerBase : public content::WebUIController {
+ public:
+  explicit MojoWebUIControllerBase(content::WebUI* contents);
+  virtual ~MojoWebUIControllerBase();
+
+  // WebUIController overrides:
+  virtual void RenderViewCreated(
+      content::RenderViewHost* render_view_host) OVERRIDE;
+
+ protected:
+  // Invoke to register mapping between binding file and resource id (IDR_...).
+  void AddMojoResourcePath(const std::string& path, int resource_id);
+
+ private:
+  // Bindings files are registered here.
+  content::WebUIDataSource* mojo_data_source_;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoWebUIControllerBase);
+};
+
 // MojoWebUIController is intended for web ui pages that use mojo. It is
 // expected that subclasses will do two things:
 // . In the constructor invoke AddMojoResourcePath() to register the bindings
 //   files, eg:
 //     AddMojoResourcePath("chrome/browser/ui/webui/omnibox/omnibox.mojom",
 //                         IDR_OMNIBOX_MOJO_JS);
 // . Override CreateUIHandler() to create the implementation of the bindings.
-class MojoWebUIController : public content::WebUIController {
+template <typename Interface>
+class MojoWebUIController : public MojoWebUIControllerBase {
  public:
-  explicit MojoWebUIController(content::WebUI* contents);
-  virtual ~MojoWebUIController();
-
-  // WebUIController overrides:
+  explicit MojoWebUIController(content::WebUI* contents)
+      : MojoWebUIControllerBase(contents), weak_factory_(this) {}
+  virtual ~MojoWebUIController() {}
   virtual void RenderViewCreated(
-      content::RenderViewHost* render_view_host) OVERRIDE;
+      content::RenderViewHost* render_view_host) OVERRIDE {
+    MojoWebUIControllerBase::RenderViewCreated(render_view_host);
+    render_view_host->GetMainFrame()->GetServiceRegistry()->
+        AddService<Interface>(
+            base::Bind(&MojoWebUIController::CreateAndStoreUIHandler,
+                       weak_factory_.GetWeakPtr()));
+  }
 
  protected:
-  // Invoke to register mapping between binding file and resource id (IDR_...).
-  void AddMojoResourcePath(const std::string& path, int resource_id);
-
   // Invoked to create the specific bindings implementation.
   virtual scoped_ptr<MojoWebUIHandler> CreateUIHandler(
-      mojo::ScopedMessagePipeHandle handle_to_page) = 0;
+      mojo::InterfaceRequest<Interface> request) = 0;
 
  private:
-  // Invoked in response to a connection from the renderer.
-  void CreateAndStoreUIHandler(mojo::ScopedMessagePipeHandle handle);
-
-  // Bindings files are registered here.
-  content::WebUIDataSource* mojo_data_source_;
+  void CreateAndStoreUIHandler(mojo::InterfaceRequest<Interface> request) {
+    ui_handler_ = CreateUIHandler(request.Pass());
+  }
 
   scoped_ptr<MojoWebUIHandler> ui_handler_;
 
   base::WeakPtrFactory<MojoWebUIController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoWebUIController);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_MOJO_WEB_UI_CONTROLLER_H_