Add an aura window property for Immersive fullscreen mode

ash/common/wm_window.cc

Index: ash/common/wm_window.cc
diff --git a/ash/common/wm_window.cc b/ash/common/wm_window.cc
index 21281fd6197dc4782a958ff33dd4013450d69869..76a419824f4b2014e17cbc65d50bf37beb310500 100644
--- a/ash/common/wm_window.cc
+++ b/ash/common/wm_window.cc
@@ -960,6 +960,11 @@ void WmWindow::OnWindowPropertyChanged(aura::Window* window,
     }
     return;
   }
+  if (key == aura::client::kImmersiveFullscreenKey) {
+    bool enable = window_->GetProperty(aura::client::kImmersiveFullscreenKey);

[sky, 2017/01/23 21:48:56]

You'll need to mirror this to a WindowManager property and register it with
PropertyConverter, otherwise when clients change the value mash won't be able to
pick it up.

[Peng, 2017/01/25 16:18:57]

Done.

+    GetWindowState()->set_in_immersive_fullscreen(enable);
+    return;
+  }
   WmWindowProperty wm_property;
   if (key == aura::client::kAlwaysOnTopKey) {
     wm_property = WmWindowProperty::ALWAYS_ON_TOP;