Do not mark from native code. Check color and call incremental marker instead.

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index 822654201129df645429fbde246c5aac53172a89..22f1aac3d831b4570c38d39046dfcff5685f7324 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -236,23 +236,10 @@ class MacroAssembler: public Assembler {
                    Label* on_black,
                    Label::Distance on_black_distance = Label::kFar);
 
-  // Detects conservatively whether an object is data-only, i.e. it does need to
-  // be scanned by the garbage collector.
-  void JumpIfDataObject(Register value,
-                        Register scratch,
-                        Label* not_data_object,
-                        Label::Distance not_data_object_distance);
-
-  // Checks the color of an object.  If the object is already grey or black
-  // then we just fall through, since it is already live.  If it is white and
-  // we can determine that it doesn't need to be scanned, then we just mark it
-  // black and fall through.  For the rest we jump to the label so the
-  // incremental marker can fix its assumptions.
-  void EnsureNotWhite(Register object,
-                      Register scratch1,
-                      Register scratch2,
-                      Label* object_is_white_and_not_data,
-                      Label::Distance distance);
+  // Checks the color of an object.  If the object is white we jump to the
+  // incremental marker.
+  void JumpIfWhite(Register value, Register scratch1, Register scratch2,
+                   Label* value_is_white, Label::Distance distance);
 
   // Notify the garbage collector that we wrote a pointer into an object.
   // |object| is the object being stored into, |value| is the object being