Consolidate javascript_dialog_manager.h and javascript_dialog_manager_impl.h

components/app_modal_dialogs/app_modal_dialog.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_H_
 #define COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/strings/string16.h"
 #include "build/build_config.h"
 
-class NativeAppModalDialog;
-
 namespace content {
 class WebContents;
 }
 
+namespace app_modal_dialogs {
+class NativeAppModalDialog;
+
 // A controller+model base class for modal dialogs.
 class AppModalDialog {
  public:
   // A union of data necessary to determine the type of message box to
   // show.
   AppModalDialog(content::WebContents* web_contents,
                  const base::string16& title);
   virtual ~AppModalDialog();
 
   // Called by the AppModalDialogQueue to show this dialog.
@@ skipping 65 matching lines @@
   AppModalDialogObserver();
   virtual ~AppModalDialogObserver();
 
   // Called when the modal dialog is shown.
   virtual void Notify(AppModalDialog* dialog) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AppModalDialogObserver);
 };
 
+}  // namespace app_modal_dialogs
+
 #endif  // COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_H_