[inspector] Make InspectorTest.sendCommand* private

test/inspector/console/let-const-with-api.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.sendCommand("Runtime.evaluate", { expression: "let a = 42;" }, step2);
+Protocol.Runtime.evaluate({ expression: "let a = 42;" }).then(step2);
 
 function step2(response)
 {
   failIfError(response);
   InspectorTest.log("first \"let a = 1;\" result: wasThrown = " + !!response.result.exceptionDetails);
-  InspectorTest.sendCommand("Runtime.evaluate", { expression: "let a = 239;" }, step3);
+  Protocol.Runtime.evaluate({ expression: "let a = 239;" }).then(step3);
 }
 
 function step3(response)
 {
   failIfError(response);
   InspectorTest.log("second \"let a = 1;\" result: wasThrown = " + !!response.result.exceptionDetails);
   if (response.result.exceptionDetails)
     InspectorTest.log("exception message: " + response.result.exceptionDetails.text + " " + response.result.exceptionDetails.exception.description);
-  InspectorTest.sendCommand("Runtime.evaluate", { expression: "a" }, step4);
+  Protocol.Runtime.evaluate({ expression: "a" }).then(step4);
 }
 
 function step4(response)
 {
   failIfError(response);
   InspectorTest.log(JSON.stringify(response.result));
   checkMethod(null);
 }
 
 var methods = [ "dir", "dirxml", "keys", "values", "profile", "profileEnd",
     "inspect", "copy", "clear",
     "debug", "undebug", "monitor", "unmonitor", "table" ];
 
 function checkMethod(response)
 {
   failIfError(response);
 
   if (response)
     InspectorTest.log(response.result.result.description);
 
   var method = methods.shift();
   if (!method)
     InspectorTest.completeTest();
 
-  InspectorTest.sendCommand("Runtime.evaluate", { expression: method, includeCommandLineAPI: true }, checkMethod);
+  Protocol.Runtime.evaluate({ expression: method, includeCommandLineAPI: true }).then(checkMethod);
 }
 
 function failIfError(response)
 {
   if (response && response.error)
     InspectorTest.log("FAIL: " + JSON.stringify(response.error));
 }