Add flag to enable immersive fullscreen for v2 apps

ash/wm/caption_buttons/frame_maximize_button.h

Index: ash/wm/caption_buttons/frame_maximize_button.h
diff --git a/ash/wm/caption_buttons/frame_maximize_button.h b/ash/wm/caption_buttons/frame_maximize_button.h
index 1539833a750ffed666a96324fcf9779ef9c0eb64..c60f7a570d1f7030c9f5a240544ab8885e2ed3c9 100644
--- a/ash/wm/caption_buttons/frame_maximize_button.h
+++ b/ash/wm/caption_buttons/frame_maximize_button.h
@@ -9,6 +9,7 @@
 #include "ash/wm/caption_buttons/maximize_bubble_frame_state.h"
 #include "ash/wm/workspace/snap_types.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "ui/aura/window_observer.h"
 #include "ui/views/controls/button/image_button.h"
@@ -19,6 +20,7 @@ class Widget;
 }
 
 namespace ash {
+class FrameMaximizeButtonObserver;
 
 namespace internal {
 class PhantomWindowController;
@@ -36,6 +38,9 @@ class ASH_EXPORT FrameMaximizeButton : public views::ImageButton,
                       views::Widget* frame);
   virtual ~FrameMaximizeButton();
 
+  void AddObserver(FrameMaximizeButtonObserver* observer);
+  void RemoveObserver(FrameMaximizeButtonObserver* observer);
+
   // Updates |snap_type_| based on a a given snap type. This is used by
   // external hover events from the button menu.
   void SnapButtonHovered(SnapType type);
@@ -44,6 +49,9 @@ class ASH_EXPORT FrameMaximizeButton : public views::ImageButton,
   // which will at the same time close the window.
   void ExecuteSnapAndCloseMenu(SnapType type);
 
+  // Called by the MaximizeBubbleController when the maximize bubble is shown.
+  void OnMaximizeBubbleShown(views::Widget* bubble);
+
   // Remove the maximize menu from the screen (and destroy it).
   void DestroyMaximizeMenu();
 
@@ -175,6 +183,8 @@ class ASH_EXPORT FrameMaximizeButton : public views::ImageButton,
   // The delay of the bubble appearance.
   int bubble_appearance_delay_ms_;
 
+  ObserverList<FrameMaximizeButtonObserver> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(FrameMaximizeButton);
 };