Devtools Animations: Support multiple frames in the animation timeline

Source/devtools/front_end/sdk/AnimationModel.js

Index: Source/devtools/front_end/sdk/AnimationModel.js
diff --git a/Source/devtools/front_end/sdk/AnimationModel.js b/Source/devtools/front_end/sdk/AnimationModel.js
index 573293b402253abe935d0204af9832f2782d23e9..1176ae2fa10c16fbd80581aac81c2e3790fa7639 100644
--- a/Source/devtools/front_end/sdk/AnimationModel.js
+++ b/Source/devtools/front_end/sdk/AnimationModel.js
@@ -63,6 +63,14 @@ WebInspector.AnimationModel.prototype = {
         this.dispatchEventToListeners(WebInspector.AnimationModel.Events.AnimationPlayerCanceled, { "playerId": playerId });
     },
 
+    /**
+     * @param {number} playbackRate
+     */
+    setPlaybackRate: function(playbackRate)
+    {
+        this._agent.setPlaybackRate(playbackRate);
+    },
+
     ensureEnabled: function()
     {
         if (this._enabled)