Abstract media galleries context menu code and use it in scan result dialog.

chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h

Index: chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h
diff --git a/chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h b/chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h
index 28754a743d8e56eb57a129e05affbb394a24f505..7a60789caecc40c90a4c4f4bac8f7b1a5ef20f7e 100644
--- a/chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h
+++ b/chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller.h
@@ -23,7 +23,12 @@ namespace extensions {
 class Extension;
 }
 
+namespace ui {
+class MenuModel;
+}
+
 class MediaGalleriesScanResultDialogController;
+class MediaGalleryContextMenu;
 class Profile;
 
 // The view.
@@ -87,6 +92,8 @@ class MediaGalleriesScanResultDialogController
 
   virtual content::WebContents* web_contents();
 
+  ui::MenuModel* GetContextMenu(MediaGalleryPrefId id);
+
  private:
   friend class MediaGalleriesScanResultDialogControllerTest;
 
@@ -166,6 +173,8 @@ class MediaGalleriesScanResultDialogController
   // The view that's showing.
   scoped_ptr<MediaGalleriesScanResultDialog> dialog_;
 
+  scoped_ptr<MediaGalleryContextMenu> context_menu_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesScanResultDialogController);
 };