[inspector] Refactor protocol-test.js

test/inspector/debugger/step-into-nested-arrow.js

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-InspectorTest.log(
+let {session, contextGroup, Protocol} = InspectorTest.start(
     'Checks that stepInto nested arrow function doesn\'t produce crash.');
 
-InspectorTest.setupScriptMap();
-InspectorTest.addScript(`
+session.setupScriptMap();
+contextGroup.addScript(`
 const rec = (x) => (y) =>
 rec();
 //# sourceURL=test.js`);
 
 Protocol.Debugger.onPaused(message => {
   InspectorTest.log("paused");
-  InspectorTest.logCallFrames(message.params.callFrames);
+  session.logCallFrames(message.params.callFrames);
   Protocol.Debugger.stepInto();
 })
 
 Protocol.Debugger.enable();
 Protocol.Debugger.setBreakpointByUrl({ url: 'test.js', lineNumber: 2 })
   .then(() => Protocol.Runtime.evaluate({ expression: 'rec(5)(4)' }))
   .then(InspectorTest.completeTest);