React immediately to memory pressure on foreground threads

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 07b967f2b8cf3bf37e093d1e3724b142d50663ad..2501544f3cd3ee13e1630922a62dd9a9cd811bb9 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -8555,10 +8555,14 @@ void Isolate::IsolateInBackgroundNotification() {
 
 void Isolate::MemoryPressureNotification(MemoryPressureLevel level) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
-  isolate->heap()->MemoryPressureNotification(level, Locker::IsLocked(this));
+  bool on_isolate_thread =
+      v8::Locker::IsActive()
+          ? isolate->thread_manager()->IsLockedByCurrentThread()
+          : i::ThreadId::Current().Equals(isolate->thread_id());
+  isolate->heap()->MemoryPressureNotification(level, on_isolate_thread);
   isolate->allocator()->MemoryPressureNotification(level);
-  isolate->compiler_dispatcher()->MemoryPressureNotification(
-      level, Locker::IsLocked(this));
+  isolate->compiler_dispatcher()->MemoryPressureNotification(level,
+                                                             on_isolate_thread);
 }
 
 void Isolate::SetRAILMode(RAILMode rail_mode) {