Devtools Animations: Add cubic bezier easing editor for animations

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 1c42e10a1ceb7c0d5bc9ff58a6060be1b69e3a5c..4bf0fc35b1ae44e727f9535d15ef34a5e7086dc4 100644
--- a/Source/devtools/front_end/sdk/AnimationModel.js
+++ b/Source/devtools/front_end/sdk/AnimationModel.js
@@ -353,7 +353,19 @@ WebInspector.AnimationModel.AnimationNode.prototype = {
      */
     easing: function()
     {
-        return this._payload.easing;
+        return this._easing || this._payload.easing;
+    },
+
+    /**
+     * @param {string} value
+     * @param {string} id
+     * @param {boolean=} callProtocol
+     */
+    setEasing: function(value, id, callProtocol)
+    {
+        this._easing = value;
+        if (callProtocol)

[dgozman, 2015/05/28 11:04:03]

What's the usecase for callProtocol == false?
When user changed the value, you have to call protocol method, right?

[samli, 2015/05/28 11:48:14]

CSS animations respond to updated styles and hence don't require a protocol
call. Invoking protocol will result in the protocol error we just added.

We could alternatively allow it to always call protocol and do nothing for CSS
animations.

+            this.target().animationAgent().setEasing(id, value);
     },
 
     __proto__: WebInspector.SDKObject.prototype