chrome/browser/ui/views/webauthn: drop “fade” hack.

With r660884, the “rotate” animation now sets the visibility of the
layer and so we no longer need to override it and use the “fade”
animation instead to avoid DCHECKs.

This effectively reverts r659735.

Change-Id: I6fbbc47a606b0bb9cbf8017e14b9f3719c16f887
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1617207
Commit-Queue: Adam Langley <agl@chromium.org>
Commit-Queue: Martin Kreichgauer <martinkr@google.com>
Auto-Submit: Adam Langley <agl@chromium.org>
Reviewed-by: Martin Kreichgauer <martinkr@google.com>
Cr-Commit-Position: refs/heads/master@{#660974}

chrome/browser/ui/views/webauthn/authenticator_request_dialog_view.cc

@@ -26,10 +26,6 @@
 #include "ui/views/vector_icons.h"
 #include "ui/views/window/dialog_client_view.h"
 
-#if defined(USE_AURA)
-#include "ui/wm/core/window_animations.h"
-#endif
-
 // static
 void ShowAuthenticatorRequestDialog(
     content::WebContents* web_contents,
@@ -260,21 +256,6 @@ void AuthenticatorRequestDialogView::Show() {
   if (!first_shown_) {
     constrained_window::ShowWebModalDialogViews(this, web_contents());
     DCHECK(GetWidget());
-
-#if defined(USE_AURA)
-    // TODO(agl): remove this to revert back to the default "rotate" animations.
-    //
-    // It appears that the rotate animation fails to handle layer visibility
-    // correctly and thus triggers DCHECKs and other issues. Using "fade" works
-    // around this until "rotate" can be fixed.
-    // https://chromium-review.googlesource.com/c/chromium/src/+/1610462
-    //
-    // When removing this, also remove the #include of window_animations.h.
-    wm::SetWindowVisibilityAnimationType(
-        GetWidget()->GetNativeWindow(),
-        wm::WINDOW_VISIBILITY_ANIMATION_TYPE_FADE);
-#endif
-
     first_shown_ = true;
   } else {
     GetWidget()->Show();