Make a clean interface for dialog callbacks.

chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h

Index: chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h
diff --git a/chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h b/chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h
index 6a05b8e5656c7c4b88c3f4fef0ca846253943ec6..4ae6d18da792a40e490e4bf831dea5667da816cc 100644
--- a/chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h
+++ b/chrome/browser/ui/app_modal_dialogs/js_modal_dialog.h
@@ -8,16 +8,15 @@
 
 #include <string>
 
+#include "base/compiler_specific.h"
 #include "base/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h"
 #include "content/browser/javascript_dialogs.h"
-#include "content/common/notification_observer.h"
-#include "content/common/notification_registrar.h"
 
-class ExtensionHost;
-class NativeAppModalDialog;
-class TabContents;
+namespace content {
+class JavaScriptDialogDelegate;
+}
 
 namespace IPC {
 class Message;
@@ -37,8 +36,7 @@ class ChromeJavaScriptDialogExtraData {
 
 // A controller + model class for JavaScript alert, confirm, prompt, and
 // onbeforeunload dialog boxes.
-class JavaScriptAppModalDialog : public AppModalDialog,
-                                 public NotificationObserver {
+class JavaScriptAppModalDialog : public AppModalDialog {
  public:
   JavaScriptAppModalDialog(content::JavaScriptDialogDelegate* delegate,
                            ChromeJavaScriptDialogExtraData* extra_data,
@@ -52,10 +50,10 @@ class JavaScriptAppModalDialog : public AppModalDialog,
   virtual ~JavaScriptAppModalDialog();
 
   // Overridden from AppModalDialog:
-  virtual NativeAppModalDialog* CreateNativeDialog();
-  virtual bool IsJavaScriptModalDialog();
-
-  content::JavaScriptDialogDelegate* delegate() const { return delegate_; }
+  virtual NativeAppModalDialog* CreateNativeDialog() OVERRIDE;
+  virtual bool IsJavaScriptModalDialog() OVERRIDE;
+  virtual void Invalidate() OVERRIDE;
+  virtual content::JavaScriptDialogDelegate* delegate() const OVERRIDE;
 
   // Callbacks from NativeDialog when the user accepts or cancels the dialog.
   void OnCancel(bool suppress_js_messages);
@@ -77,20 +75,10 @@ class JavaScriptAppModalDialog : public AppModalDialog,
   bool is_before_unload_dialog() const { return is_before_unload_dialog_; }
 
  private:
-  // Overridden from NotificationObserver:
-  virtual void Observe(NotificationType type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details);
-
-  // Initializes for notifications to listen.
-  void InitNotifications();
-
   // Notifies the delegate with the result of the dialog.
   void NotifyDelegate(bool success, const string16& prompt_text,
                       bool suppress_js_messages);
 
-  NotificationRegistrar registrar_;
-
   // An implementation of the client interface to provide supporting methods
   // and receive results.
   content::JavaScriptDialogDelegate* delegate_;

[Evan Martin, 2011/06/29 22:01:52]

This is confusing; AppModalDialog already has a protected delegate_ member.

[Avi (use Gerrit), 2011/06/29 22:09:29]

Right, but this as a subclass requires the expanded subclass delegate. I'm not
sure of a better clean way to do it; thoughts?

[Evan Martin, 2011/06/29 22:53:09]

I polled my office and they came up with:

content::JavaScriptDialogDelegate* delegate() const {
  return static_cast<content::JavaScriptDialogDelegate*>(delegate_);
}

[Avi (use Gerrit), 2011/06/29 23:19:48]

You were objecting to the storage rather than the override with the covariant
return type? Oh, I can do that. Done.