Fix incremental marking speed accelleration and start incremental marking when old space is almost …

src/incremental-marking.h

Index: src/incremental-marking.h
diff --git a/src/incremental-marking.h b/src/incremental-marking.h
index fc5a978cc445b6d4627b0aaf5632d700201c3855..7b6927e8738b93e4b0ce89addd40b830a87e918b 100644
--- a/src/incremental-marking.h
+++ b/src/incremental-marking.h
@@ -110,10 +110,7 @@ class IncrementalMarking {
   static const intptr_t kMarkingSpeedAccelleration = 2;
   static const intptr_t kMaxMarkingSpeed = 1000;
 
-  void OldSpaceStep(intptr_t allocated) {
-    Step(allocated * kFastMarking / kInitialMarkingSpeed,
-         GC_VIA_STACK_GUARD);
-  }
+  void OldSpaceStep(intptr_t allocated);
 
   void Step(intptr_t allocated, CompletionAction action);