Moves CustomFrameViewAsh to common

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 0f029eb4256211a2cd35848c071d4aca6c42a666..790809a04ff5439e65cc8d56d170fc882ce10a30 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -59,6 +59,7 @@ class WindowResizer;
 class WindowSelectorController;
 class WmActivationObserver;
 class WmDisplayObserver;
+class WmImmersiveFullscreenController;
 class WmWindow;
 
 enum class TaskSwitchSource;
@@ -260,6 +261,9 @@ class ASH_EXPORT WmShell {
   virtual std::unique_ptr<ScopedDisableInternalMouseAndKeyboard>
   CreateScopedDisableInternalMouseAndKeyboard() = 0;
 
+  virtual std::unique_ptr<WmImmersiveFullscreenController>
+  CreateImmersiveFullscreenController() = 0;
+
   // Called after maximize mode has started, windows might still animate though.
   void OnMaximizeModeStarted();