extensions: Add ExtensionView interface.

chrome/browser/ui/views/extensions/extension_dialog.h

Index: chrome/browser/ui/views/extensions/extension_dialog.h
diff --git a/chrome/browser/ui/views/extensions/extension_dialog.h b/chrome/browser/ui/views/extensions/extension_dialog.h
index 8e182bd9e74c12e7d48c9faa9665a4210ff59b63..ec9688e7d53797f4b2a3764e356d94e8b22fd8dc 100644
--- a/chrome/browser/ui/views/extensions/extension_dialog.h
+++ b/chrome/browser/ui/views/extensions/extension_dialog.h
@@ -24,6 +24,8 @@ namespace extensions {
 class ExtensionHost;
 }
 
+class ExtensionViewViews;
+
 // Modal dialog containing contents provided by an extension.
 // Dialog is automatically centered in the owning window and has fixed size.
 // For example, used by the Chrome OS file browser.
@@ -136,6 +138,8 @@ class ExtensionDialog : public views::WidgetDelegate,
   // The observer of this popup.
   ExtensionDialogObserver* observer_;
 
+  ExtensionViewViews* view_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionDialog);
 };