[profiler] Introduce Tracing CPU profiler V8 API.

src/profiler/tracing-cpu-profiler.cc

+// 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.
+
+#include "src/profiler/tracing-cpu-profiler.h"
+
+#include "src/v8.h"
+
+namespace v8 {
+
+std::unique_ptr<TracingCpuProfiler> TracingCpuProfiler::Create(
+    v8::Isolate* isolate) {
+  return std::unique_ptr<TracingCpuProfiler>(
+      new internal::TracingCpuProfilerImpl(
+          reinterpret_cast<internal::Isolate*>(isolate)));
+}
+
+namespace internal {
+
+TracingCpuProfilerImpl::TracingCpuProfilerImpl(Isolate* isolate) {}
+
+TracingCpuProfilerImpl::~TracingCpuProfilerImpl() {}
+
+}  // namespace internal
+}  // namespace v8