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 f672bb08ddda69b6b46a8ef791cb3d8b0fab2930..63ba3e73ac9bfafe459808c04c7bb492d0d2f433 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -55,6 +55,7 @@ class WindowResizer;
 class WindowSelectorController;
 class WmActivationObserver;
 class WmDisplayObserver;
+class WmImmersiveFullscreenController;
 class WmWindow;
 
 enum class TaskSwitchSource;
@@ -247,6 +248,9 @@ 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();