[promises] Add %WaitForPromise runtime call to allow tests to reliably wait for promises to be fini…

src/isolate.h

 // Copyright 2012 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_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <memory>
 #include <queue>
 
@@ skipping 1225 matching lines @@
   ManagedObjectFinalizer* RegisterForReleaseAtTeardown(
       void* value, ManagedObjectFinalizer::Deleter deleter);
 
   // Unregister a previously registered value from release at
   // isolate teardown, deleting the ManagedObjectFinalizer.
   // This transfers the responsibility of the previously managed value's
   // deletion to the caller. Pass by pointer, because *finalizer_ptr gets
   // reset to nullptr.
   void UnregisterFromReleaseAtTeardown(ManagedObjectFinalizer** finalizer_ptr);
 
+  // Can be used by tests to force d8 to wait for certain things to run.
+  inline void IncrementWaitCount() { wait_count_++; }
+  inline void DecrementWaitCount() { wait_count_--; }
+  inline int GetWaitCount() { return wait_count_; }
+
  protected:
   explicit Isolate(bool enable_serializer);
   bool IsArrayOrObjectPrototype(Object* object);
 
  private:
   friend struct GlobalState;
   friend struct InitializeGlobalState;
 
   // These fields are accessed through the API, offsets must be kept in sync
   // with v8::internal::Internals (in include/v8.h) constants. This is also
@@ skipping 265 matching lines @@
 #ifdef USE_SIMULATOR
   base::Mutex simulator_i_cache_mutex_;
 #endif
 
   bool allow_atomics_wait_;
 
   ManagedObjectFinalizer managed_object_finalizers_list_;
 
   size_t total_regexp_code_generated_;
 
+  int wait_count_ = 0;
+
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
   friend class HeapTester;
   friend class OptimizingCompileDispatcher;
   friend class SweeperThread;
   friend class ThreadManager;
   friend class Simulator;
   friend class StackGuard;
   friend class ThreadId;
   friend class v8::Isolate;
@@ skipping 216 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_