Add web_animations.js to the list of public externs files.

Closes #2134.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=257436744

externs/browser/web_animations.js

@@ -0,0 +1,342 @@
+/*
+ * Copyright 2016 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.
+ */
+
+
+/**
+ * @fileoverview Basic externs for the Web Animations API. This is not
+ * nessecarily exhaustive. For more information, see the spec-
+ *   https://w3c.github.io/web-animations
+ * @externs
+ */
+
+
+/**
+ * @param {!Array<!Object>} frames
+ * @param {(number|KeyframeAnimationOptions)=} options
+ * @return {!Animation}
+ */
+Element.prototype.animate = function(frames, options) {};
+
+/**
+ * @return {!Array<!Animation>}
+ */
+Element.prototype.getAnimations = function() {};
+
+
+/**
+ * @constructor
+ * @param {AnimationEffectReadOnly=} effect
+ * @param {AnimationTimeline=} timeline
+ * @implements {EventTarget}
+ */
+var Animation = function(effect, timeline) {};
+
+/** @override */
+Animation.prototype.addEventListener = function(type, listener, options) {};
+
+/** @override */
+Animation.prototype.removeEventListener = function(type, listener, options) {};
+
+/** @override */
+Animation.prototype.dispatchEvent = function(evt) {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.cancel = function() {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.finish = function() {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.pause = function() {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.play = function() {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.reverse = function() {};
+
+/** @type {number} */
+Animation.prototype.currentTime;
+
+/** @type {AnimationEffectReadOnly} */
+Animation.prototype.effect;
+
+/** @type {!Promise<void>} */
+Animation.prototype.finished;
+
+/** @type {string} */
+Animation.prototype.id;
+
+/** @type {?function(!Event)} */
+Animation.prototype.oncancel;
+
+/** @type {?function(!Event)} */
+Animation.prototype.onfinish;
+
+/** @type {number} */
+Animation.prototype.playbackRate;
+
+/** @type {string} */
+Animation.prototype.playState;
+
+/** @type {!Promise<void>} */
+Animation.prototype.ready;
+
+/** @type {number} */
+Animation.prototype.startTime;
+
+/** @type {!AnimationTimeline} */
+Animation.prototype.timeline;
+
+
+/**
+ * @interface
+ */
+var AnimationEffectReadOnly = function() {};
+
+/**
+ * @return {!ComputedTimingProperties}
+ */
+AnimationEffectReadOnly.prototype.getComputedTiming = function() {};
+
+/** @type {!AnimationEffectTiming} */
+AnimationEffectReadOnly.prototype.timing;
+
+
+/**
+ * @constructor
+ * @param {Element} target
+ * @param {(!Array<!Object<string, *>>|!Object<string, !Array<*>>)} frames
+ * @param {(number|AnimationEffectTimingProperties)=} options
+ * @implements {AnimationEffectReadOnly}
+ */
+var KeyframeEffectReadOnly = function(target, frames, options) {};
+
+/** @override */
+KeyframeEffectReadOnly.prototype.getComputedTiming = function() {};
+
+/** @override */
+KeyframeEffectReadOnly.prototype.timing;
+
+
+/**
+ * @constructor
+ * @param {Element} target
+ * @param {(!Array<!Object<string, *>>|!Object<string, !Array<*>>)} frames
+ * @param {(number|AnimationEffectTimingProperties)=} options
+ * @extends {KeyframeEffectReadOnly}
+ */
+var KeyframeEffect = function(target, frames, options) {};
+
+
+/**
+ * @record
+ */
+var AnimationEffectTimingProperties = function() {};
+
+/** @type {number|undefined} */
+AnimationEffectTimingProperties.prototype.delay;
+
+/** @type {number|undefined} */
+AnimationEffectTimingProperties.prototype.endDelay;
+
+/** @type {string|undefined} */
+AnimationEffectTimingProperties.prototype.fill;
+
+/** @type {number|undefined} */
+AnimationEffectTimingProperties.prototype.iterationStart;
+
+/** @type {number|undefined} */
+AnimationEffectTimingProperties.prototype.iterations;
+
+/** @type {number|string|undefined} */
+AnimationEffectTimingProperties.prototype.duration;
+
+/** @type {string|undefined} */
+AnimationEffectTimingProperties.prototype.direction;
+
+/** @type {string|undefined} */
+AnimationEffectTimingProperties.prototype.easing;
+
+
+/**
+ * @record
+ * @extends {AnimationEffectTimingProperties}
+ */
+var KeyframeAnimationOptions = function() {};
+
+/** @type {string|undefined} */
+KeyframeAnimationOptions.prototype.id;
+
+
+/**
+ * @record
+ * @extends {AnimationEffectTimingProperties}
+ */
+var ComputedTimingProperties = function() {};
+
+/** @type {number} */
+ComputedTimingProperties.prototype.endTime;
+
+/** @type {number} */
+ComputedTimingProperties.prototype.activeDuration;
+
+/** @type {?number} */
+ComputedTimingProperties.prototype.localTime;
+
+/** @type {?number} */
+ComputedTimingProperties.prototype.progress;
+
+/** @type {?number} */
+ComputedTimingProperties.prototype.currentIteration;
+
+
+/**
+ * @interface
+ */
+var AnimationEffectTimingReadOnly = function() {};
+
+/** @type {number} */
+AnimationEffectTimingReadOnly.prototype.delay;
+
+/** @type {number} */
+AnimationEffectTimingReadOnly.prototype.endDelay;
+
+/** @type {string} */
+AnimationEffectTimingReadOnly.prototype.fill;
+
+/** @type {number} */
+AnimationEffectTimingReadOnly.prototype.iterationStart;
+
+/** @type {number} */
+AnimationEffectTimingReadOnly.prototype.iterations;
+
+/** @type {number|string} */
+AnimationEffectTimingReadOnly.prototype.duration;
+
+/** @type {string} */
+AnimationEffectTimingReadOnly.prototype.direction;
+
+/** @type {string} */
+AnimationEffectTimingReadOnly.prototype.easing;
+
+
+/**
+ * @interface
+ * @extends {AnimationEffectTimingReadOnly}
+ */
+var AnimationEffectTiming = function() {};
+
+
+/**
+ * @interface
+ */
+var AnimationTimeline = function() {};
+
+/** @type {?number} */
+AnimationTimeline.prototype.currentTime;
+
+
+/**
+ * @constructor
+ * @implements {AnimationTimeline}
+ */
+var DocumentTimeline = function() {};
+
+/** @override */
+DocumentTimeline.prototype.currentTime;
+
+
+/** @type {!DocumentTimeline} */
+Document.prototype.timeline;
+
+/**
+ * Externs for the Web Animations API (Level 2 / Groups).
+ *
+ * This defines externs for the "-next" version of the Web Animations API
+ * polyfill found online at:
+ *    https://github.com/web-animations/web-animations.js
+ *
+ * These features are NOT natively implemented in browsers and are not clearly
+ * part of the official spec. This is NOT intended to be exhaustive, and
+ * requires the base externs from web-animations.js.
+ *
+ */
+
+
+/** @type {Element} */
+KeyframeEffectReadOnly.prototype.target;
+
+/** @type {?function(number, !KeyframeEffect, !Animation)|undefined} */
+KeyframeEffectReadOnly.prototype.onsample;
+
+
+/**
+ * @param {!AnimationEffectReadOnly} effect
+ * @return {!Animation}
+ */
+DocumentTimeline.prototype.play = function(effect) {};
+
+/**
+ * @return {!Array<!Animation>}
+ */
+DocumentTimeline.prototype.getAnimations = function() {};
+
+
+/**
+ * @param {!Array<!AnimationEffectReadOnly>} children
+ * @param {AnimationEffectTimingProperties=} timing
+ * @constructor
+ * @implements {AnimationEffectReadOnly}
+ */
+var SequenceEffect = function(children, timing) {};
+
+/** @override */
+SequenceEffect.prototype.getComputedTiming = function() {};
+
+/** @override */
+SequenceEffect.prototype.timing;
+
+/** @type {!Array<!AnimationEffectReadOnly>} */
+SequenceEffect.prototype.children;
+
+
+/**
+ * @param {!Array<!AnimationEffectReadOnly>} children
+ * @param {AnimationEffectTimingProperties=} timing
+ * @constructor
+ * @implements {AnimationEffectReadOnly}
+ */
+var GroupEffect = function(children, timing) {};
+
+/** @override */
+GroupEffect.prototype.getComputedTiming = function() {};
+
+/** @override */
+GroupEffect.prototype.timing;
+
+/** @type {!Array<!AnimationEffectReadOnly>} */
+GroupEffect.prototype.children;