[heap] New heuristics for incremental marking step size.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 102265149555ae7ce245725c8cbf5a58e2f4defa..56f208c540ac71560478169d8cb63925e34fa82c 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -3129,17 +3129,6 @@ void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
   Label need_incremental;
   Label need_incremental_pop_object;
 
-  __ movp(regs_.scratch0(), Immediate(~Page::kPageAlignmentMask));
-  __ andp(regs_.scratch0(), regs_.object());
-  __ movp(regs_.scratch1(),
-         Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset));
-  __ subp(regs_.scratch1(), Immediate(1));
-  __ movp(Operand(regs_.scratch0(),
-                 MemoryChunk::kWriteBarrierCounterOffset),
-         regs_.scratch1());
-  __ j(negative, &need_incremental);
-
   // Let's look at the color of the object:  If it is not black we don't have
   // to inform the incremental marker.
   __ JumpIfBlack(regs_.object(),