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

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index ae345dd2c7bd428c99cce760b71ce35f3fcc5638..e9a010461b1e7643f0ad28813c3a163a24351456 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -37,6 +37,8 @@
 #include "src/d8.h"
 #include "src/ostreams.h"
 
+#include "include/v8-sampler.h"
+#include "include/v8-tracing-controller.h"
 #include "include/libplatform/libplatform.h"
 #ifndef V8_SHARED
 #include "src/api.h"
@@ -2448,6 +2450,8 @@ int Shell::Main(int argc, char* argv[]) {
 
   v8::V8::InitializePlatform(g_platform);
   v8::V8::Initialize();
+  // Initialize tracing controller support
+  TracingController::SetUp();
   if (options.natives_blob || options.snapshot_blob) {
     v8::V8::InitializeExternalStartupData(options.natives_blob,
                                           options.snapshot_blob);
@@ -2499,6 +2503,7 @@ int Shell::Main(int argc, char* argv[]) {
       return 0;
     }
 #endif
+    TracingController::StartTracing(isolate);
 
     if (options.stress_opt || options.stress_deopt) {
       Testing::SetStressRunType(options.stress_opt
@@ -2554,7 +2559,9 @@ int Shell::Main(int argc, char* argv[]) {
     os << *profiler;
   }
 #endif  // !V8_SHARED
+  TracingController::StopTracing();
   isolate->Dispose();
+  TracingController::TearDown();
   V8::Dispose();
   V8::ShutdownPlatform();
   delete g_platform;