Support higher CPU profiler sampling rate on posix systems

src/cpu-profiler.h

Index: src/cpu-profiler.h
diff --git a/src/cpu-profiler.h b/src/cpu-profiler.h
index 1dd405e5d76a8bd97a083560b4a1283641b7fbc2..a9cc61129c5258bf3aeeacb8f15253283015bd02 100644
--- a/src/cpu-profiler.h
+++ b/src/cpu-profiler.h
@@ -140,7 +140,9 @@ class CodeEventsContainer {
 // methods called by event producers: VM and stack sampler threads.
 class ProfilerEventsProcessor : public Thread {
  public:
-  explicit ProfilerEventsProcessor(ProfileGenerator* generator);
+  ProfilerEventsProcessor(ProfileGenerator* generator,
+                          Sampler* sampler,
+                          int period_in_useconds);
   virtual ~ProfilerEventsProcessor() {}
 
   // Thread control.
@@ -163,8 +165,14 @@ class ProfilerEventsProcessor : public Thread {
   bool ProcessCodeEvent();
   bool ProcessTicks();
 
+  void ProcessEventsAndDoSample();
+  void ProcessEventsAndYield();
+
   ProfileGenerator* generator_;
+  Sampler* sampler_;
   bool running_;
+  // Sampling period in microseconds.
+  const int period_in_useconds_;
   UnboundQueue<CodeEventsContainer> events_buffer_;
   SamplingCircularQueue ticks_buffer_;
   UnboundQueue<TickSampleEventRecord> ticks_from_vm_buffer_;