Introduce :-internal-shadow-host-has-appearance pseudo class, and apply it to METER element.

third_party/WebKit/Source/core/html/shadow/AppearanceSwitchElement.h

Index: third_party/WebKit/Source/core/html/shadow/AppearanceSwitchElement.h
diff --git a/third_party/WebKit/Source/core/html/shadow/AppearanceSwitchElement.h b/third_party/WebKit/Source/core/html/shadow/AppearanceSwitchElement.h
deleted file mode 100644
index a1781b4bfe3d93c3ba409442561f0c5c0c5932d1..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/html/shadow/AppearanceSwitchElement.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef AppearanceSwitchElement_h
-#define AppearanceSwitchElement_h
-
-#include "core/html/HTMLDivElement.h"
-
-namespace blink {
-
-class AppearanceSwitchElement final : public HTMLDivElement {
-public:
-    enum Mode {
-        ShowIfHostHasAppearance,
-        ShowIfHostHasNoAppearance,
-    };
-    static AppearanceSwitchElement* create(Document&, Mode);
-
-private:
-    AppearanceSwitchElement(Document&, Mode);
-    PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
-
-    const Mode m_mode;
-};
-
-} // namespace blink
-#endif // AppearanceSwitchElement_h