[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/app_window/app_window.h

Index: extensions/browser/app_window/app_window.h
diff --git a/extensions/browser/app_window/app_window.h b/extensions/browser/app_window/app_window.h
index 1112d38a035226049dc2c48bfe4bc2912644d13e..10267f6476aac3fd8ccd844cbc2ef24bebd35060 100644
--- a/extensions/browser/app_window/app_window.h
+++ b/extensions/browser/app_window/app_window.h
@@ -15,6 +15,7 @@
 #include "components/web_modal/web_contents_modal_dialog_manager_delegate.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
+#include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/extension_icon_image.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "ui/base/ui_base_types.h"  // WindowShowState
@@ -70,6 +71,8 @@ class AppWindowContents {
 
   virtual content::WebContents* GetWebContents() const = 0;
 
+  virtual extensions::WindowController* GetWindowController() const = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(AppWindowContents);
 };
@@ -80,6 +83,7 @@ class AppWindow : public content::WebContentsDelegate,
                   public content::WebContentsObserver,
                   public web_modal::WebContentsModalDialogManagerDelegate,
                   public IconImage::Observer,
+                  public ExtensionFunctionDispatcher::Delegate,
                   public ExtensionRegistryObserver {
  public:
   enum WindowType {
@@ -408,6 +412,10 @@ class AppWindow : public content::WebContentsDelegate,
   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
   void DidFirstVisuallyNonEmptyPaint() override;
 
+  // ExtensionFunctionDispatcher::Delegate implementation.
+  WindowController* GetExtensionWindowController() const override;
+  content::WebContents* GetAssociatedWebContents() const override;
+
   // ExtensionRegistryObserver implementation.
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
                            const Extension* extension,