[Chromecast] Fixes for 4798685c merge

Remove aura::Env from WMHelperCastShell:
Upstream has removed aura::Env from the WMHelper interface, this CL
removes it from the CastShell specialization as well.

NoGnCheck views_delegate:
The header include and dep in the BUILD.gn file are both guarded
correctly, but gncheck still thinks the include is illegal. Don't
gncheck the include.

Bug: b/133174544
Test: Chromecast build
Change-Id: Id5de601311c8285416172cb1e97b74957f341fd1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1628999Reviewed-by: Sergey Volk <servolk@chromium.org>
Auto-Submit: Fergus Simpson <afergs@chromium.org>
Commit-Queue: Fergus Simpson <afergs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663772}

chromecast/browser/cast_browser_main_parts.cc

@@ -99,7 +99,7 @@
 #include "chromecast/graphics/cast_window_manager_aura.h"
 #include "components/viz/service/display/overlay_strategy_underlay_cast.h"  // nogncheck
 #include "ui/display/screen.h"
-#include "ui/views/views_delegate.h"
+#include "ui/views/views_delegate.h"  // nogncheck
 #else
 #include "chromecast/graphics/cast_window_manager_default.h"
 #endif

chromecast/browser/exo/wm_helper_cast_shell.h

@@ -126,7 +126,6 @@ class WMHelperCastShell : public WMHelper, public VSyncTimingManager::Delegate {
   };
 
   chromecast::CastWindowManagerAura* cast_window_manager_aura_;
-  aura::Env* const env_;
   chromecast::CastScreen* cast_screen_;
   CastDisplayObserver display_observer_;
   LifetimeManager lifetime_manager_;