Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components-chromium/polymer/src/lib/style-util-extracted.js

+
+
+  (function() {
+
+    function toCssText(rules, callback) {
+      if (typeof rules === 'string') {
+        rules = Polymer.CssParse.parse(rules);
+      } 
+      if (callback) {
+        forEachStyleRule(rules, callback);
+      }
+      return Polymer.CssParse.stringify(rules);
+    }
+
+    function forEachStyleRule(node, cb) {
+      var s = node.selector;
+      var skipRules = false;
+      if (s) {
+        if ((s.indexOf(AT_RULE) !== 0) && (s.indexOf(MIXIN_SELECTOR) !== 0)) {
+          cb(node);
+        }
+        skipRules = (s.indexOf(KEYFRAME_RULE) >= 0) || 
+          (s.indexOf(MIXIN_SELECTOR) >= 0);
+      }
+      var r$ = node.rules;
+      if (r$ && !skipRules) {
+        for (var i=0, l=r$.length, r; (i<l) && (r=r$[i]); i++) {
+          forEachStyleRule(r, cb);
+        }
+      }
+    }
+
+    // add a string of cssText to the document.
+    function applyCss(cssText, moniker, target, lowPriority) {
+      var style = document.createElement('style');
+      if (moniker) {
+        style.setAttribute('scope', moniker);
+      }
+      style.textContent = cssText;
+      target = target || document.head;
+      if (lowPriority) {
+        var n$ = target.querySelectorAll('style[scope]');
+        var ref = n$.length ? n$[n$.length-1].nextSibling : target.firstChild;
+        target.insertBefore(style, ref);
+     } else {
+        target.appendChild(style);
+      }
+      return style;
+    }
+
+    var AT_RULE = '@';
+    var KEYFRAME_RULE = 'keyframe';
+    var MIXIN_SELECTOR = '--';
+
+    // exports
+    Polymer.StyleUtil = {
+      parser: Polymer.CssParse,
+      applyCss: applyCss,
+      forEachStyleRule: forEachStyleRule,
+      toCssText: toCssText
+    };
+
+  })();
+