app-shell: Introduce a ShellRendererMainDelegate.

apps/shell/renderer/shell_content_renderer_client.h

Index: apps/shell/renderer/shell_content_renderer_client.h
diff --git a/apps/shell/renderer/shell_content_renderer_client.h b/apps/shell/renderer/shell_content_renderer_client.h
index 506704c6939b81fab9391602c72d7f28420ed480..3527a5af9fd06ddf4ccb6e380b745c55838ef20b 100644
--- a/apps/shell/renderer/shell_content_renderer_client.h
+++ b/apps/shell/renderer/shell_content_renderer_client.h
@@ -19,11 +19,12 @@ namespace apps {
 
 class ShellExtensionsClient;
 class ShellExtensionsRendererClient;
+class ShellRendererMainDelegate;
 
 // Renderer initialization and runtime support for app_shell.
 class ShellContentRendererClient : public content::ContentRendererClient {
  public:
-  ShellContentRendererClient();
+  explicit ShellContentRendererClient(ShellRendererMainDelegate* delegate);
   virtual ~ShellContentRendererClient();
 
   // content::ContentRendererClient implementation:
@@ -42,6 +43,7 @@ class ShellContentRendererClient : public content::ContentRendererClient {
   virtual bool ShouldEnableSiteIsolationPolicy() const OVERRIDE;
 
  private:
+  ShellRendererMainDelegate* delegate_;
   scoped_ptr<ShellExtensionsClient> extensions_client_;
   scoped_ptr<ShellExtensionsRendererClient> extensions_renderer_client_;
   scoped_ptr<extensions::DispatcherDelegate> extension_dispatcher_delegate_;