[inspector] Refactor protocol-test.js

test/inspector/debugger/step-over-another-context-group.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 stepping with more then one context group.');
 
+var contextGroup1 = new InspectorTest.ContextGroup();
+var session1 = contextGroup1.connect();
+session1.setupScriptMap();
+
+let contextGroup2 = new InspectorTest.ContextGroup();
+let session2 = contextGroup2.connect();
+session2.setupScriptMap();
+
 (async function test() {
-  InspectorTest.setupScriptMap();
-  await Protocol.Debugger.enable();
-  let contextGroup = InspectorTest.createContextGroup();
-  let session = InspectorTest.createSession(contextGroup);
-  InspectorTest.setupScriptMap(session);
-  await session.Protocol.Debugger.enable({});
-  Protocol.Runtime.evaluate({expression: 'debugger'});
-  session.Protocol.Runtime.evaluate({expression: 'setTimeout(() => { debugger }, 0)'});
-  Protocol.Runtime.evaluate({expression: 'setTimeout(() => 42, 0)'});
-  await waitPauseAndDumpLocation(InspectorTest.session);
-  Protocol.Debugger.stepOver();
-  await Protocol.Debugger.oncePaused();
-  Protocol.Debugger.stepOver();
-  await waitPauseAndDumpLocation(InspectorTest.session);
-  await session.Protocol.Debugger.disable({});
-  await Protocol.Debugger.disable();
+  await session1.Protocol.Debugger.enable();
+  await session2.Protocol.Debugger.enable({});
+  session1.Protocol.Runtime.evaluate({expression: 'debugger'});
+  session2.Protocol.Runtime.evaluate({expression: 'setTimeout(() => { debugger }, 0)'});
+  session1.Protocol.Runtime.evaluate({expression: 'setTimeout(() => 42, 0)'});
+  await waitPauseAndDumpLocation(session1);
+  session1.Protocol.Debugger.stepOver();
+  await session1.Protocol.Debugger.oncePaused();
+  session1.Protocol.Debugger.stepOver();
+  await waitPauseAndDumpLocation(session1);
+  await session2.Protocol.Debugger.disable({});
+  await session1.Protocol.Debugger.disable();
   InspectorTest.completeTest();
 })();
 
 async function waitPauseAndDumpLocation(session) {
   var message = await session.Protocol.Debugger.oncePaused();
   InspectorTest.log('paused at:');
-  await InspectorTest.logSourceLocation(message.params.callFrames[0].location, session);
+  await session.logSourceLocation(message.params.callFrames[0].location);
   return message;
 }