Fix Polymer licensing issues

third_party/web-animations-js/sources/src/interpolation.js

-// Copyright 2014 Google Inc. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-//     You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//     See the License for the specific language governing permissions and
-// limitations under the License.
-
-(function(scope, testing) {
-
-  function interpolate(from, to, f) {
-    if ((typeof from == 'number') && (typeof to == 'number')) {
-      return from * (1 - f) + to * f;
-    }
-    if ((typeof from == 'boolean') && (typeof to == 'boolean')) {
-      return f < 0.5 ? from : to;
-    }
-
-    WEB_ANIMATIONS_TESTING && console.assert(
-        Array.isArray(from) && Array.isArray(to),
-        'If interpolation arguments are not numbers or bools they must be arrays');
-
-    if (from.length == to.length) {
-      var r = [];
-      for (var i = 0; i < from.length; i++) {
-        r.push(interpolate(from[i], to[i], f));
-      }
-      return r;
-    }
-    throw 'Mismatched interpolation arguments ' + from + ':' + to;
-  }
-
-  scope.Interpolation = function(from, to, convertToString) {
-    return function(f) {
-      return convertToString(interpolate(from, to, f));
-    }
-  };
-
-  if (WEB_ANIMATIONS_TESTING) {
-    testing.interpolate = interpolate;
-  }
-
-})(webAnimations1, webAnimationsTesting);