[inspector] Refactor protocol-test.js

test/inspector/debugger/async-stack-await.js

 // Copyright 2016 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('Checks that async stacks works for async/await');
+let {session, contextGroup, Protocol} = InspectorTest.start('Checks that async stacks works for async/await');
 
-InspectorTest.addScript(`
+contextGroup.addScript(`
 async function foo1() {
   debugger;
   return Promise.resolve();
 }
 
 async function foo2() {
   await Promise.resolve();
   debugger;
   await Promise.resolve();
   debugger;
   await foo1();
   await Promise.all([ Promise.resolve() ]).then(foo1);
   debugger;
 }
 
 async function test() {
   await foo2();
 }
 //# sourceURL=test.js`, 7, 26);
 
-InspectorTest.setupScriptMap();
+session.setupScriptMap();
 Protocol.Debugger.onPaused(message => {
-  InspectorTest.logCallFrames(message.params.callFrames);
-  InspectorTest.logAsyncStackTrace(message.params.asyncStackTrace);
+  session.logCallFrames(message.params.callFrames);
+  session.logAsyncStackTrace(message.params.asyncStackTrace);
   InspectorTest.log('');
   Protocol.Debugger.resume();
 });
 
 Protocol.Debugger.enable();
 Protocol.Debugger.setAsyncCallStackDepth({ maxDepth: 128 });
 Protocol.Runtime.evaluate({ expression: 'test()//# sourceURL=expr.js',
     awaitPromise: true })
   .then(InspectorTest.logMessage)
   .then(InspectorTest.completeTest);