[Refactor] Replace kFullscreenUsesMinimalChromeKey with WindowState::hide_shelf_when_fullscreen()

ash/wm/window_properties.h

Index: ash/wm/window_properties.h
diff --git a/ash/wm/window_properties.h b/ash/wm/window_properties.h
index 1bf28ff7ed2e8890736d7a7cd59690898c1cadbf..9f13fadb054068270c850ad84010da42631a1773 100644
--- a/ash/wm/window_properties.h
+++ b/ash/wm/window_properties.h
@@ -29,12 +29,6 @@ namespace internal {
 // the fullscreen state.
 extern const aura::WindowProperty<bool>* const kAnimateToFullscreenKey;
 
-// A property key to indicate whether there is any chrome at all that cannot be
-// hidden when the window is fullscreen. This is unrelated to whether the full
-// chrome can be revealed by hovering the mouse at the top of the screen.
-ASH_EXPORT extern const aura::WindowProperty<bool>* const
-    kFullscreenUsesMinimalChromeKey;
-
 // If this is set to true, the window stays in the same root window
 // even if the bounds outside of its root window is set.
 // This is exported as it's used in the tests.