[heap] Respect idle deadline in AdvanceIncrementalMarking more carefully.

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

Index: src/heap/gc-idle-time-handler.h
diff --git a/src/heap/gc-idle-time-handler.h b/src/heap/gc-idle-time-handler.h
index 39dea7e1ff942c7d4e9c78004c6f184a2b3f9b3f..709aa913da88cd9941f913107ef4a4a506c07d26 100644
--- a/src/heap/gc-idle-time-handler.h
+++ b/src/heap/gc-idle-time-handler.h
@@ -113,6 +113,10 @@ class GCIdleTimeHandler {
   // Incremental marking step time.
   static const size_t kIncrementalMarkingStepTimeInMs = 1;
 
+  // Minimum incremental marking step time.
+  static const size_t kMinIncrementalMarkingStepTimeInMs =
+      kIncrementalMarkingStepTimeInMs + 1;
+
   static const size_t kMinTimeForOverApproximatingWeakClosureInMs;
 
   // Number of times we will return a Nothing action in the current mode