Consolidate javascript_dialog_manager.h and javascript_dialog_manager_impl.h

components/app_modal_dialogs/app_modal_dialog.h

Index: components/app_modal_dialogs/app_modal_dialog.h
diff --git a/components/app_modal_dialogs/app_modal_dialog.h b/components/app_modal_dialogs/app_modal_dialog.h
index 12d7f5cd6f5d0039db1e7a9126ed9b87fb7fd2e2..2a9cf896a03f6b59b118f57b5e28f13ac52fd91a 100644
--- a/components/app_modal_dialogs/app_modal_dialog.h
+++ b/components/app_modal_dialogs/app_modal_dialog.h
@@ -11,12 +11,13 @@
 #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:
@@ -102,4 +103,6 @@ class AppModalDialogObserver {
   DISALLOW_COPY_AND_ASSIGN(AppModalDialogObserver);
 };
 
+}  // namespace app_modal_dialogs
+
 #endif  // COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_H_