[inspector] Refactor protocol-test.js

test/inspector/debugger/set-async-call-stack-depth.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 with new stack traces it's almost
 // imposible to hit limit.
-InspectorTest.log('Checks that we report not more then maxDepth call chains.');
+let {session, contextGroup, Protocol} = InspectorTest.start('Checks that we report not more then maxDepth call chains.');
 
-InspectorTest.addScript(`
+contextGroup.addScript(`
 function promisesChain(num) {
   var p = Promise.resolve();
   for (var i = 0; i < num - 1; ++i) {
     p = p.then(() => 42);
   }
   return p;
 }
 `);
 
 Protocol.Debugger.enable();
@@ skipping 50 matching lines @@
 }
 
 function dumpCaptured(stack) {
   let count = 0;
   while (stack) {
     ++count;
     stack = stack.parent;
   }
   InspectorTest.log('reported: ' + count + '\n');
 }