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

src/compiler-dispatcher/compiler-dispatcher.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_
 #define V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_
 
 #include <map>
 #include <memory>
 #include <unordered_set>
@@ skipping 53 matching lines @@
  public:
   enum class BlockingBehavior { kBlock, kDontBlock };
 
   CompilerDispatcher(Isolate* isolate, Platform* platform,
                      size_t max_stack_size);
   ~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;
 
   // Blocks until the given function is compiled (and does so as fast as
   // possible). Returns true if the compile job was succesful.
   bool FinishNow(Handle<SharedFunctionInfo> function);
 
   // Aborts a given job. Blocks if requested.
   void Abort(Handle<SharedFunctionInfo> function, BlockingBehavior blocking);
 
   // Aborts all jobs. Blocks if requested.
   void AbortAll(BlockingBehavior blocking);
 
   // Memory pressure notifications from the embedder.
   void MemoryPressureNotification(v8::MemoryPressureLevel level,
                                   bool is_isolate_locked);
 
  private:
+  FRIEND_TEST(CompilerDispatcherTest, EnqueueAndStep);
   FRIEND_TEST(CompilerDispatcherTest, IdleTaskSmallIdleTime);
   FRIEND_TEST(IgnitionCompilerDispatcherTest, CompileOnBackgroundThread);
   FRIEND_TEST(IgnitionCompilerDispatcherTest, FinishNowWithBackgroundTask);
   FRIEND_TEST(IgnitionCompilerDispatcherTest,
               AsyncAbortAllPendingBackgroundTask);
   FRIEND_TEST(IgnitionCompilerDispatcherTest,
               AsyncAbortAllRunningBackgroundTask);
   FRIEND_TEST(IgnitionCompilerDispatcherTest, FinishNowDuringAbortAll);
 
   typedef std::multimap<std::pair<int, int>,
@@ skipping 60 matching lines @@
   base::AtomicValue<bool> block_for_testing_;
   base::Semaphore semaphore_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilerDispatcher);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_