Use deadline in IdleNotification.

src/heap/gc-idle-time-handler.cc

Index: src/heap/gc-idle-time-handler.cc
diff --git a/src/heap/gc-idle-time-handler.cc b/src/heap/gc-idle-time-handler.cc
index 4103b78a348c81e3be0b60b030a04d107eaa4ea1..1bdc597d91085d20c1ffb28ba390bcc2553bd437 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -166,9 +166,9 @@ bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
 // request, we finalize sweeping here.
 // (6) If incremental marking is in progress, we perform a marking step. Note,
 // that this currently may trigger a full garbage collection.
-GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
+GCIdleTimeAction GCIdleTimeHandler::Compute(double idle_time,
                                             HeapState heap_state) {
-  if (idle_time_in_ms == 0) {
+  if (idle_time <= 0.0) {
     if (heap_state.incremental_marking_stopped) {
       if (ShouldDoContextDisposalMarkCompact(
               heap_state.contexts_disposed,
@@ -179,6 +179,8 @@ GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
     return GCIdleTimeAction::Nothing();
   }
 
+  size_t idle_time_in_ms = static_cast<size_t>(idle_time);
+
   if (ShouldDoScavenge(
           idle_time_in_ms, heap_state.new_space_capacity,
           heap_state.used_new_space_size,