DevTools: clean up scripts folder

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 307 matching lines @@
         /**
          * @param {string} a
          */
         function testArrowFunctionReferencingThisMissingAnnotation(a)
         {
             (x => this._q.push(x))(a);
         }
 
     }
 };