[inspector] Refactor protocol-test.js

test/inspector/debugger/promise-chain-when-limit-hit.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.
+
 // TODO(kozyatinskiy): fix or remove it later.
+let {session, contextGroup, Protocol} = InspectorTest.start('Tests how async promise chains behave when reaching the limit of stacks');
+
 (async function test(){
   InspectorTest.log('Checks correctness of promise chains when limit hit');
   await Protocol.Runtime.enable();
   await Protocol.Debugger.enable();
   Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
 
   await setMaxAsyncTaskStacks(3);
   runWithAsyncChainPromise(3, 'console.trace()');
   InspectorTest.logMessage(await Protocol.Runtime.onceConsoleAPICalled());
 
@@ skipping 27 matching lines @@
   Protocol.Runtime.evaluate({
     expression: `Promise.resolve()${then.repeat(len - 1)}${pause}`
   });
 }
 
 async function setMaxAsyncTaskStacks(max) {
   let expression = `inspector.setMaxAsyncTaskStacks(${max})`;
   InspectorTest.log(expression);
   await Protocol.Runtime.evaluate({expression});
 }