Wires up immersive mode for chrome and mash

ash/common/frame/custom_frame_view_ash.h

 // Copyright (c) 2012 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 ASH_COMMON_FRAME_CUSTOM_FRAME_VIEW_ASH_H_
 #define ASH_COMMON_FRAME_CUSTOM_FRAME_VIEW_ASH_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/views/window/non_client_view.h"
 
 namespace views {
 class Widget;
 }
 
 namespace ash {
 
 class FrameCaptionButtonContainerView;
 class HeaderView;
 class ImmersiveFullscreenController;
+class ImmersiveFullscreenControllerDelegate;
 
 // A NonClientFrameView used for packaged apps, dialogs and other non-browser
 // windows. It supports immersive fullscreen. When in immersive fullscreen, the
 // client view takes up the entire widget and the window header is an overlay.
 // The window header overlay slides onscreen when the user hovers the mouse at
 // the top of the screen. See also views::CustomFrameView and
 // BrowserNonClientFrameViewAsh.
 class ASH_EXPORT CustomFrameViewAsh : public views::NonClientFrameView {
  public:
   // Internal class name.
   static const char kViewClassName[];
 
-  explicit CustomFrameViewAsh(views::Widget* frame);
+  // |enable_immersive| controls whether ImmersiveFullscreenController is
+  // created for the CustomFrameViewAsh; if true and a WindowStateDelegate has
+  // not been set on the WindowState associated with |frame|, then an
+  // ImmersiveFullscreenController is created.
+  // If ImmersiveFullscreenControllerDelegate is not supplied, HeaderView is
+  // used as the ImmersiveFullscreenControllerDelegate.
+  explicit CustomFrameViewAsh(

[James Cook, 2016/08/24 17:00:32]

I think this would be clearer with two constructors:

CustomFrameViewAsh(frame)
CustomFrameViewAsh(frame, immersive_delegate, enable_immersive)

and have the first one use C++11 constructor delegation to call the second.

(Or change all the call sites, there are only 6 existing ones.)

[sky, 2016/08/24 19:23:28]

Can you outline why you feel having two constructors is clearer? It seems like
all you get with two constructors is the opportunity for different
documentation, but that's covered here. One benefit of a single constructor like
this is it's easy to see the defaults. Two constructors means you have to look
to the definition to see the behavior.

[James Cook, 2016/08/24 19:56:29]

This allows "new CustomFrameViewAsh(frame, delegate)" without the
enable_immersive parameter, which felt like a case you might not want. I don't
feel that strongly, though.

+      views::Widget* frame,
+      ImmersiveFullscreenControllerDelegate* immersive_delegate = nullptr,
+      bool enable_immersive = true);
   ~CustomFrameViewAsh() override;
 
   // Inits |immersive_fullscreen_controller| so that the controller reveals
   // and hides |header_view_| in immersive fullscreen.
   // CustomFrameViewAsh does not take ownership of
   // |immersive_fullscreen_controller|.
   void InitImmersiveFullscreenControllerForView(
       ImmersiveFullscreenController* immersive_fullscreen_controller);
 
   // Sets the active and inactive frame colors. Note the inactive frame color
@@ skipping 40 matching lines @@
 
   // Height from top of window to top of client area.
   int NonClientTopBorderHeight() const;
 
   // Not owned.
   views::Widget* frame_;
 
   // View which contains the title and window controls.
   HeaderView* header_view_;
 
+  ImmersiveFullscreenControllerDelegate* immersive_delegate_;
+
   DISALLOW_COPY_AND_ASSIGN(CustomFrameViewAsh);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_FRAME_CUSTOM_FRAME_VIEW_ASH_H_