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

ash/ash_switches.cc

Index: ash/ash_switches.cc
diff --git a/ash/ash_switches.cc b/ash/ash_switches.cc
index 394e5a6cea65596c0bad2f033fb097e3acd07cda..e76b91b6a599814ec14c2ede82f6eff90f3e4b7b 100644
--- a/ash/ash_switches.cc
+++ b/ash/ash_switches.cc
@@ -151,11 +151,6 @@ const char kAshHideNotificationsForFactory[] =
 // "1024x768*2" sets the scale factor to 2 for a high DPI display.
 const char kAshHostWindowBounds[] = "ash-host-window-bounds";
 
-// Hides the small tab indicators at the top of the screen during immersive
-// fullscreen mode.
-const char kAshImmersiveHideTabIndicators[] =
-    "ash-immersive-hide-tab-indicators";
-
 // OEM-supplied wallpaper (as paths to trusted, non-user-writable JPEG files).
 const char kAshOemWallpaperLarge[] = "ash-oem-wallpaper-large";
 const char kAshOemWallpaperSmall[] = "ash-oem-wallpaper-small";