Add ability to enqueue SharedFunctionInfos so they can run on bg threads

src/compiler-dispatcher/compiler-dispatcher.h

Index: src/compiler-dispatcher/compiler-dispatcher.h
diff --git a/src/compiler-dispatcher/compiler-dispatcher.h b/src/compiler-dispatcher/compiler-dispatcher.h
index 9e27439f242955106e419e97430cdbcb0303d2ec..088b3bbccfa8505c157abe5acd23326b59dcfabe 100644
--- a/src/compiler-dispatcher/compiler-dispatcher.h
+++ b/src/compiler-dispatcher/compiler-dispatcher.h
@@ -71,6 +71,11 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
   // Returns true if a job was enqueued.
   bool Enqueue(Handle<SharedFunctionInfo> function);
 
+  // Like Enqueue, but also advances the job so that it can potentially
+  // continue running on a background thread (if at all possible). Returns
+  // true if the job was enqueued.
+  bool EnqueueAndStep(Handle<SharedFunctionInfo> function);
+
   // Returns true if there is a pending job for the given function.
   bool IsEnqueued(Handle<SharedFunctionInfo> function) const;
 
@@ -89,6 +94,7 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
                                   bool is_isolate_locked);
 
  private:
+  FRIEND_TEST(CompilerDispatcherTest, EnqueueAndStep);
   FRIEND_TEST(CompilerDispatcherTest, IdleTaskSmallIdleTime);
   FRIEND_TEST(IgnitionCompilerDispatcherTest, CompileOnBackgroundThread);
   FRIEND_TEST(IgnitionCompilerDispatcherTest, FinishNowWithBackgroundTask);