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 fbd2bb69d655949321f04f73a0cb3c5e310d210d..c1c33ce57408e6984fadd4958106ff38880f51f6 100644
--- a/Source/devtools/front_end/sdk/AnimationModel.js
+++ b/Source/devtools/front_end/sdk/AnimationModel.js
@@ -264,6 +264,31 @@ WebInspector.AnimationModel.AnimationPlayer.prototype = {
             this._source.deferredNode().resolve(nodeResolved.bind(this));
     },
 
+    /**
+     * @param {string} value
+     */
+    setEasing: function(value)
+    {
+        /**
+         * @param {?WebInspector.DOMNode} node
+         * @this {!WebInspector.AnimationModel.AnimationPlayer}
+         */
+        function nodeResolved(node)
+        {
+            if (!node)
+                return;
+            var animationProperty = this.type() === "CSSTransition" ? "transition" : "animation";
+            var style = node.getAttribute("style") || "";
+            style = style.replace(new RegExp("\\s*(-webkit-)?" + animationProperty + "-timing-function:[^;]*;?\\s*", "g"), "");
+            node.setAttributeValue("style", String.sprintf("%s %s-timing-function: %s !important;", style, animationProperty, value));
+        }
+
+        this.target().animationAgent().setEasing(this.id(), value);
+        // TODO (samli): Update CSS rules instead. (crbug.com/492937)
+        if (this.type() !== "WebAnimation")
+            this._source.deferredNode().resolve(nodeResolved.bind(this));
+    },
+
     __proto__: WebInspector.SDKObject.prototype
 }