Devtools Animations: Don't wait for empty transitions to start

third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js

Index: third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js b/third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js
index 882e2b1ab73c5186d121b2fa85f1412429942803..aa5ec0b52f951cf83ed090d02ac1b35cffe33504 100644
--- a/third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/animation/AnimationModel.js
@@ -23,8 +23,7 @@ WebInspector.AnimationModel = function(target)
 }
 
 WebInspector.AnimationModel.Events = {
-    AnimationGroupStarted: "AnimationGroupStarted",
-    AnimationCanceled: "AnimationCanceled"
+    AnimationGroupStarted: "AnimationGroupStarted"
 }
 
 WebInspector.AnimationModel.prototype = {
@@ -43,6 +42,12 @@ WebInspector.AnimationModel.prototype = {
         this._pendingAnimations.push(id);
     },
 
+    _animationCancelled: function(id)
+    {
+        this._pendingAnimations.remove(id);
+        this._flushPendingAnimationsIfNeeded();
+    },
+
     /**
      * @param {!AnimationAgent.Animation} payload
      */
@@ -50,7 +55,11 @@ WebInspector.AnimationModel.prototype = {
     {
         var animation = WebInspector.AnimationModel.Animation.parsePayload(this.target(), payload);
         this._animationsById.set(animation.id(), animation);
+        this._flushPendingAnimationsIfNeeded();
+    },
 
+    _flushPendingAnimationsIfNeeded: function()
+    {
         for (var id of this._pendingAnimations) {
             if (!this._animationsById.get(id))
                 return;
@@ -752,6 +761,15 @@ WebInspector.AnimationDispatcher.prototype = {
 
     /**
      * @override
+     * @param {string} id
+     */
+    animationCancelled: function(id)
+    {
+        this._animationModel._animationCancelled(id);
+    },
+
+    /**
+     * @override
      * @param {!AnimationAgent.Animation} payload
      */
     animationStarted: function(payload)