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

third_party/WebKit/Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
@@ skipping 5146 matching lines @@
                     { "name": "id", "type": "string", "description": "Id of the animation that was created." }
                 ],
                 "description": "Event for each animation that has been created."
             },
             {
                 "name": "animationStarted",
                 "parameters": [
                     { "name": "animation", "$ref": "Animation", "description": "Animation that was started." }
                 ],
                 "description": "Event for animation that has been started."
+            },
+            {
+                "name": "animationCancelled",

[pfeldman, 2015/11/09 23:00:10]

animationCanceled as American English would put it. 

+                "parameters": [
+                    { "name": "id", "type": "string", "description": "Id of the animation that was cancelled."}
+                ],
+                "description": "Event for when an animation has been cancelled."
             }
         ]
     },
     {
         "domain": "Accessibility",
         "hidden": true,
         "types": [
             {
                 "id": "AXNodeId",
                 "type": "string",
@@ skipping 114 matching lines @@
                 ],
                 "returns": [
                     { "name": "accessibilityNode", "$ref": "AXNode", "description": "The <code>Accessibility.AXNode</code> for this DOM node, if it exists.", "optional": true }
                 ],
                 "description": "Fetches the accessibility node for this DOM node, if it exists.",
                 "hidden": true
             }
         ]
     }]
 }