Create libsampler as V8 sampler library.

src/profiler/cpu-profiler.cc

Index: src/profiler/cpu-profiler.cc
diff --git a/src/profiler/cpu-profiler.cc b/src/profiler/cpu-profiler.cc
index 5e4a444e8c957c37163714bf360d973ddf1eb972..dbd0434b0aa4852d8863651b8ad647175996a268 100644
--- a/src/profiler/cpu-profiler.cc
+++ b/src/profiler/cpu-profiler.cc
@@ -21,7 +21,7 @@ static const int kProfilerStackSize = 64 * KB;
 
 
 ProfilerEventsProcessor::ProfilerEventsProcessor(ProfileGenerator* generator,
-                                                 Sampler* sampler,
+                                                 sampler::Sampler* sampler,
                                                  base::TimeDelta period)
     : Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)),
       generator_(generator),
@@ -566,7 +566,7 @@ void CpuProfiler::StartProcessorIfNotStarted() {
   saved_is_logging_ = logger->is_logging_;
   logger->is_logging_ = false;
   generator_ = new ProfileGenerator(profiles_);
-  Sampler* sampler = logger->sampler();
+  sampler::Sampler* sampler = logger->sampler();
   processor_ = new ProfilerEventsProcessor(
       generator_, sampler, sampling_interval_);
   is_profiling_ = true;
@@ -612,7 +612,8 @@ void CpuProfiler::StopProcessorIfLastProfile(const char* title) {
 
 void CpuProfiler::StopProcessor() {
   Logger* logger = isolate_->logger();
-  Sampler* sampler = reinterpret_cast<Sampler*>(logger->ticker_);
+  sampler::Sampler* sampler =
+      reinterpret_cast<sampler::Sampler*>(logger->ticker_);
   is_profiling_ = false;
   processor_->StopSynchronously();
   delete processor_;