Remove <picture> and <source>.

sky/engine/core/html/HTMLPictureElement.h

Index: sky/engine/core/html/HTMLPictureElement.h
diff --git a/sky/engine/core/html/HTMLPictureElement.h b/sky/engine/core/html/HTMLPictureElement.h
deleted file mode 100644
index d9490eeb596b61df045bfaaf0b0b106781f2b276..0000000000000000000000000000000000000000
--- a/sky/engine/core/html/HTMLPictureElement.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2014 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 HTMLPictureElement_h
-#define HTMLPictureElement_h
-
-#include "core/html/HTMLElement.h"
-
-namespace blink {
-
-class HTMLPictureElement final : public HTMLElement {
-    DEFINE_WRAPPERTYPEINFO();
-public:
-    DECLARE_NODE_FACTORY(HTMLPictureElement);
-
-    void sourceOrMediaChanged();
-
-protected:
-    explicit HTMLPictureElement(Document&);
-
-private:
-    virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
-};
-
-} // namespace blink
-
-#endif // HTMLPictureElement_h