Remove preemption thread and API

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 740cce00476a3ab66ea35fbf48e411f7bbc06da2..ba5788942347592d45d7ca24761740de6b734f80 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1770,7 +1770,6 @@ Isolate::Isolate()
       write_iterator_(NULL),
       global_handles_(NULL),
       eternal_handles_(NULL),
-      context_switcher_(NULL),
       thread_manager_(NULL),
       fp_stubs_generated_(false),
       has_installed_extensions_(false),
@@ -1907,10 +1906,6 @@ void Isolate::Deinit() {
 
     delete deoptimizer_data_;
     deoptimizer_data_ = NULL;
-    if (FLAG_preemption) {
-      v8::Locker locker(reinterpret_cast<v8::Isolate*>(this));
-      v8::Locker::StopPreemption(reinterpret_cast<v8::Isolate*>(this));
-    }
     builtins_.TearDown();
     bootstrapper_->TearDown();
 
@@ -2027,8 +2022,6 @@ Isolate::~Isolate() {
   delete write_iterator_;
   write_iterator_ = NULL;
 
-  delete context_switcher_;
-  context_switcher_ = NULL;
   delete thread_manager_;
   thread_manager_ = NULL;
 
@@ -2249,11 +2242,6 @@ bool Isolate::Init(Deserializer* des) {
     PreallocatedStorageInit(preallocated_memory_thread_->length() / 4);
   }
 
-  if (FLAG_preemption) {
-    v8::Locker locker(reinterpret_cast<v8::Isolate*>(this));
-    v8::Locker::StartPreemption(reinterpret_cast<v8::Isolate*>(this), 100);
-  }
-
 #ifdef ENABLE_DEBUGGER_SUPPORT
   debug_->SetUp(create_heap_objects);
 #endif