Use smaller heap growing factor in idle notification to start incremental marking when there is idl…

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 f953c87b3b81049345b2f23e15b451eb694c844d..ed89b8bc770a07aac81313ddc21ce8487c67565d 100644
--- a/src/heap/gc-idle-time-handler.h
+++ b/src/heap/gc-idle-time-handler.h
@@ -119,9 +119,12 @@ class GCIdleTimeHandler {
   static const int kIdleScavengeThreshold;
 
   // This is the maximum scheduled idle time. Note that it can be more than
-  // 16 ms when there is currently no rendering going on.
+  // 16.66 ms when there is currently no rendering going on.
   static const size_t kMaxScheduledIdleTime = 50;
 
+  // The maximum idle time when frames are rendered is 16.66ms.
+  static const size_t kMaxFrameRenderingIdleTime = 17;
+
   // We conservatively assume that in the next kTimeUntilNextIdleEvent ms
   // no idle notification happens.
   static const size_t kTimeUntilNextIdleEvent = 100;