DevTools: fix jsdoc validator to recognize `this' usage within arrow functions

third_party/WebKit/Source/devtools/scripts/jsdoc-validator/tests/this.js

 this.foo = this.foo + 1; // OK - outside of function.
 
 function f() {
     this.foo = this.foo + 1; // OK - global |this|.
 }
 
 /**
  * @constructor
  */
 function TypeOne() {
@@ skipping 264 matching lines @@
          * @this {Object}
          */
         function callbackNotReferencingThisAnnotated()
         {
         }
         this.memberTwo(callbackNotReferencingThisAnnotated); // OK - Has @this annotation, but does not reference |this|.
     },
 
     memberTwo: function(arg) {}
 }
+
+/**
+ * @constructor
+ */
+function ReceiverWithArrowsTest()
+{
+    this._q = [];
+}
+
+ReceiverWithArrowsTest.prototype = {
+    /**
+     * @param {string} s
+     */
+    memberOne: function(s)
+    {
+        /**
+         * @param {string} a
+         * @this {C}
+         */
+        function testArrowFunctionReferencingThis(a)
+        {
+            (x => this._q.push(x))(a);
+        }
+
+        /**
+         * @param {string} a
+         * @this {C}
+         */
+        function testNestedArrowFunctionReferencingThis(a)
+        {
+            (x => (y => this._q.push(y))(x))(a);
+        }
+
+        /**
+         * @param {string} a
+         */
+        function testArrowFunctionReferencingThisMissingAnnotation(a)
+        {
+            (x => this._q.push(x))(a);
+        }
+
+    }
+};