Return start/end profiling time in microseconds instead of milliseconds

test/cctest/test-cpu-profiler.cc

Index: test/cctest/test-cpu-profiler.cc
diff --git a/test/cctest/test-cpu-profiler.cc b/test/cctest/test-cpu-profiler.cc
index 3f0fb802b9772c57d4709c096f53e6fdc723e7f6..daf8db615142001fcebab78e6103e5137f427179 100644
--- a/test/cctest/test-cpu-profiler.cc
+++ b/test/cctest/test-cpu-profiler.cc
@@ -415,13 +415,13 @@ TEST(ProfileStartEndTime) {
   v8::HandleScope scope(env->GetIsolate());
   v8::CpuProfiler* cpu_profiler = env->GetIsolate()->GetCpuProfiler();
 
-  double time_before_profiling = i::OS::TimeCurrentMillis();
+  int64_t time_before_profiling = i::OS::Ticks();
   v8::Local<v8::String> profile_name = v8::String::New("test");
   cpu_profiler->StartCpuProfiling(profile_name);
   const v8::CpuProfile* profile = cpu_profiler->StopCpuProfiling(profile_name);
   CHECK(time_before_profiling <= profile->GetStartTime());
   CHECK(profile->GetStartTime() <= profile->GetEndTime());
-  CHECK(profile->GetEndTime() <= i::OS::TimeCurrentMillis());
+  CHECK(profile->GetEndTime() <= i::OS::Ticks());
 }