Extract NativeAppWindow from src/extensions

extensions/browser/app_window/app_window_client.h

Index: extensions/browser/app_window/app_window_client.h
diff --git a/extensions/browser/app_window/app_window_client.h b/extensions/browser/app_window/app_window_client.h
index a832b23044d37a6a337738f62a94beff88116abc..10bf612651199a2c7cddc20c90539d8e5aa62ef5 100644
--- a/extensions/browser/app_window/app_window_client.h
+++ b/extensions/browser/app_window/app_window_client.h
@@ -6,17 +6,21 @@
 #define EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_CLIENT_H_
 
 #include "base/callback_forward.h"
-#include "extensions/browser/app_window/app_window.h"
 
 namespace content {
 class BrowserContext;
 class WebContents;
 }
 
+namespace native_app_window {
+class AppWindowCreateParams;
+class NativeAppWindow;
+}
+
 namespace extensions {
 
+class AppWindow;
 class Extension;
-class NativeAppWindow;
 
 // Sets up global state for the app window system. Should be Set() once in each
 // process. This should be implemented by the client of the app window system.
@@ -31,9 +35,9 @@ class AppWindowClient {
                                      const Extension* extension) = 0;
 
   // Creates a new extensions::NativeAppWindow for |window|.
-  virtual NativeAppWindow* CreateNativeAppWindow(
+  virtual native_app_window::NativeAppWindow* CreateNativeAppWindow(
       AppWindow* window,
-      const AppWindow::CreateParams& params) = 0;
+      const native_app_window::AppWindowCreateParams& params) = 0;
 
   // Opens DevTools window and runs the callback.
   virtual void OpenDevToolsWindow(content::WebContents* web_contents,