[inspector] Refactor protocol-test.js

test/inspector/cpu-profiler/coverage.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.
 
 // Flags: --allow-natives-syntax --no-always-opt --opt
 
 var source =
 `
 function fib(x) {
   if (x < 2) return 1;
@@ skipping 32 matching lines @@
         return function nested_3() {}
       }
     }
   }
   function nested_4() {}
   return nested_0();
 })();
 f()()();
 `;
 
-InspectorTest.log("Test collecting code coverage data with Profiler.collectCoverage.");
+let {session, contextGroup, Protocol} = InspectorTest.start("Test collecting code coverage data with Profiler.collectCoverage.");
 
 function ClearAndGC() {
   return Protocol.Runtime.evaluate({ expression: "fib = g = f = h = is_optimized = null;" })
              .then(GC);
 }
 
 function GC() {
   return Protocol.HeapProfiler.enable()
            .then(() => Protocol.HeapProfiler.collectGarbage())
            .then(() => Protocol.HeapProfiler.disable());
@@ skipping 194 matching lines @@
       .then(() => Protocol.Runtime.evaluate({ expression: "f()" }))
       .then(Protocol.Profiler.takePreciseCoverage)
       .then(LogSorted)
       .then(Protocol.Profiler.stopPreciseCoverage)
       .then(Protocol.Profiler.disable)
       .then(Protocol.Runtime.disable)
       .then(ClearAndGC)
       .then(next);
   },
 ]);