[inspector] Refactor protocol-test.js

test/inspector/debugger/protocol-string-to-double-locale.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.
 
+let {session, contextGroup, Protocol} = InspectorTest.start('Tests that double numbers are parsed and serialized correctly on different locales');
+
 (async function() {
   InspectorTest.log('This test verifies that we correctly parse doubles with non-US locale');
   utils.setlocale("fr_CA.UTF-8");
   Protocol.Debugger.enable();
   Protocol.Runtime.evaluate({
     expression: 'inspector.breakProgram(\'\', JSON.stringify({a: 0.5}))'});
   let message = await Protocol.Debugger.oncePaused();
   InspectorTest.logObject(message.params.data || {});
   Protocol.Debugger.resume();
 
   Protocol.Runtime.evaluate({
     expression: 'inspector.breakProgram(\'\', JSON.stringify({a: 1}))'});
   message = await Protocol.Debugger.oncePaused();
   InspectorTest.logObject(message.params.data || {});
   Protocol.Debugger.resume();
 
   InspectorTest.completeTest();
 })();