[inspector] Refactor protocol-test.js

test/inspector/debugger/step-over-caught-exception.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.addScript(
+let {session, contextGroup, Protocol} = InspectorTest.start('Tests that stepping over caught exception will pause when asked for');
+
+contextGroup.addScript(
 `function testFunction()
 {
   function foo()
   {
     try {
       throw new Error();
     } catch (e) {
     }
   }
   debugger;
@@ skipping 51 matching lines @@
 
   Protocol.Runtime.onConsoleAPICalled(function(messageObject)
   {
     if (messageObject.params.args[0].value === "completed") {
       if (commands.length)
         InspectorTest.log("[FAIL]: execution was resumed too earlier.")
       InspectorTest.completeTest();
     }
   });
 }