[inspector] Refactor protocol-test.js

test/inspector/heap-profiler/take-heap-snapshot-on-pause.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('Checks that takeHeapSnapshot uses empty accessing_context for access \
+let {session, contextGroup, Protocol} = InspectorTest.start('Checks that takeHeapSnapshot uses empty accessing_context for access \
 checks.');
 
-InspectorTest.addScript(`
+contextGroup.addScript(`
 function testFunction() {
   var array = [ inspector.createObjectWithStrictCheck() ];
   debugger;
 }
 //# sourceURL=test.js`);
 
 Protocol.Debugger.onScriptParsed(message => {
   Protocol.HeapProfiler.takeHeapSnapshot({ reportProgress: false })
     .then(() => Protocol.Debugger.resume());
 });
 
 Protocol.Debugger.enable();
 Protocol.HeapProfiler.enable();
 Protocol.Runtime.evaluate({ expression: 'testFunction()' })
   .then(() => InspectorTest.log('Successfully finished'))
   .then(InspectorTest.completeTest);