[WIP]Create a V8 sampler library and tracing controller.

src/profiler/cpu-profiler.h

Index: src/profiler/cpu-profiler.h
diff --git a/src/profiler/cpu-profiler.h b/src/profiler/cpu-profiler.h
index 1a1249c8b2309c44dbc65fe9c78e1616427df483..0de30c74e0c4e2a8e0a196cd5a3762a5bee255c3 100644
--- a/src/profiler/cpu-profiler.h
+++ b/src/profiler/cpu-profiler.h
@@ -15,6 +15,9 @@
 #include "src/profiler/sampler.h"
 
 namespace v8 {
+
+class V8Sampler;
+
 namespace internal {
 
 // Forward declarations.
@@ -128,7 +131,7 @@ class CodeEventsContainer {
 class ProfilerEventsProcessor : public base::Thread {
  public:
   ProfilerEventsProcessor(ProfileGenerator* generator,
-                          Sampler* sampler,
+                          V8Sampler* sampler,
                           base::TimeDelta period);
   virtual ~ProfilerEventsProcessor();
 
@@ -166,7 +169,7 @@ class ProfilerEventsProcessor : public base::Thread {
   SampleProcessingResult ProcessOneSample();
 
   ProfileGenerator* generator_;
-  Sampler* sampler_;
+  V8Sampler* sampler_;
   base::Atomic32 running_;
   const base::TimeDelta period_;  // Samples & code events processing period.
   LockedQueue<CodeEventsContainer> events_buffer_;