Add d8 API for spawning function on a new thread.

src/d8.h

Index: src/d8.h
diff --git a/src/d8.h b/src/d8.h
index 3b06059323c81f1a4f7810d348d07a095790a22b..21cba88a3eda2fe82e4b99601947e7dabe414cd2 100644
--- a/src/d8.h
+++ b/src/d8.h
@@ -8,6 +8,7 @@
 #ifndef V8_SHARED
 #include "src/allocation.h"
 #include "src/hashmap.h"
+#include "src/list.h"
 #include "src/smart-pointers.h"
 #include "src/v8.h"
 #else
@@ -167,6 +168,41 @@ class SourceGroup {
   int end_offset_;
 };
 
+#ifndef V8_SHARED
+class Worker {
+ public:
+  Worker();
+  ~Worker();
+
+  void StartExecuteInThread(Isolate* isolate, const char* function_string,
+                            const v8::SharedArrayBuffer::Contents& contents =
+                                v8::SharedArrayBuffer::Contents());
+  Handle<Value> WaitForThread(Isolate* isolate);
+
+ private:
+  class WorkerThread : public base::Thread {
+   public:
+    explicit WorkerThread(Worker* worker)
+        : base::Thread(base::Thread::Options("WorkerThread")),
+          worker_(worker) {}
+
+    virtual void Run() { worker_->ExecuteInThread(); }
+
+   private:
+    Worker* worker_;
+  };
+
+  void ExecuteInThread();
+  void Cleanup();
+
+  base::Mutex mutex_;
+  base::Thread* thread_;
+  char* script_;
+  char* result_json_;
+  v8::SharedArrayBuffer::Contents contents_;
+};
+#endif  // !V8_SHARED
+
 
 class ShellOptions {
  public:
@@ -246,6 +282,7 @@ class Shell : public i::AllStatic {
   static void CollectGarbage(Isolate* isolate);
 
 #ifndef V8_SHARED
+  static void CleanupWorker(Isolate* isolate);
   static Handle<Array> GetCompletions(Isolate* isolate,
                                       Handle<String> text,
                                       Handle<String> full);
@@ -289,6 +326,8 @@ class Shell : public i::AllStatic {
     args.GetReturnValue().Set(ReadFromStdin(args.GetIsolate()));
   }
   static void Load(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void WorkerJoin(const v8::FunctionCallbackInfo<v8::Value>& args);
   // The OS object on the global object contains methods for performing
   // operating system calls:
   //
@@ -341,6 +380,8 @@ class Shell : public i::AllStatic {
   static base::OS::MemoryMappedFile* counters_file_;
   static base::Mutex context_mutex_;
   static const base::TimeTicks kInitialTicks;
+  static Worker worker_;
+  static i::List<v8::SharedArrayBuffer::Contents> externalized_shared_contents_;
 
   static Counter* GetCounter(const char* name, bool is_histogram);
   static void InstallUtilityScript(Isolate* isolate);