[Media Router] Animate transition between sink list and filter views.

chrome/browser/resources/media_router/externs.js

Index: chrome/browser/resources/media_router/externs.js
diff --git a/chrome/browser/resources/media_router/externs.js b/chrome/browser/resources/media_router/externs.js
index c81db5b89b93e35aa4b1da9932b6a78ee3af6fef..577907d3b9418475ae17051e0d1c05abbe995a63 100644
--- a/chrome/browser/resources/media_router/externs.js
+++ b/chrome/browser/resources/media_router/externs.js
@@ -19,3 +19,47 @@ var InputDeviceCapabilities;
 
 /** @type {?InputDeviceCapabilities} */
 Event.prototype.sourceCapabilities;
+
+/**
+ * @interface
+ */
+var AnimationEffect = function() {};
+
+/**
+ * @param {Element} target
+ * @param {!Array<!Object>} frames
+ * @param {(number|Object)=} timing
+ * @constructor
+ * @implements {AnimationEffect}
+ */
+var KeyframeEffect = function(target, frames, timing) {};
+
+/**
+ * @param {!Array<!AnimationEffect>} group
+ * @constructor
+ * @implements {AnimationEffect}
+ */
+var GroupEffect = function(group) {};
+
+/**
+ * @interface
+ */
+var Animation = function() {};
+
+/**
+ * @return {undefined}
+ */
+Animation.prototype.cancel = function() {};
+
+/**
+ * @type {!Promise}
+ */
+Animation.prototype.finished;
+
+document.timeline = {};
+
+/**
+ * @param {!AnimationEffect} effect
+ * @return {!Animation}
+ */
+document.timeline.play = function(effect) {};