1 files changed, 40 insertions, 0 deletions
diff --git a/catapult/third_party/polymer/components/shadycss/src/unscoped-style-handler.js b/catapult/third_party/polymer/components/shadycss/src/unscoped-style-handler.js
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+++ b/catapult/third_party/polymer/components/shadycss/src/unscoped-style-handler.js
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+/**
+@license
+Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+*/
+
+'use strict';
+
+/** @type {!Set<string>} */
+const styleTextSet = new Set();
+
+export const scopingAttribute = 'shady-unscoped';
+
+/**
+ * Add a specifically-marked style to the document directly, and only one copy of that style.
+ *
+ * @param {!HTMLStyleElement} style
+ * @return {undefined}
+ */
+export function processUnscopedStyle(style) {
+  const text = style.textContent;
+  if (!styleTextSet.has(text)) {
+    styleTextSet.add(text);
+    const newStyle = style.cloneNode(true);
+    document.head.appendChild(newStyle);
+  }
+}
+
+/**
+ * Check if a style is supposed to be unscoped
+ * @param {!HTMLStyleElement} style
+ * @return {boolean} true if the style has the unscoping attribute
+ */
+export function isUnscopedStyle(style) {
+  return style.hasAttribute(scopingAttribute);
+}
+\ No newline at end of file