Remove conservative sweeping.

src/heap/mark-compact.h

Index: src/heap/mark-compact.h
diff --git a/src/heap/mark-compact.h b/src/heap/mark-compact.h
index 7a8b1063a9414a6735c40bb1fcb7169628fab8a4..29ae1d51f888759d2feef69154e2e0867edc5ebb 100644
--- a/src/heap/mark-compact.h
+++ b/src/heap/mark-compact.h
@@ -544,8 +544,6 @@ class MarkCompactCollector {
   void EnableCodeFlushing(bool enable);
 
   enum SweeperType {
-    PARALLEL_CONSERVATIVE,
-    CONCURRENT_CONSERVATIVE,
     PARALLEL_PRECISE,
     CONCURRENT_PRECISE,
     PRECISE
@@ -561,12 +559,6 @@ class MarkCompactCollector {
   void VerifyOmittedMapChecks();
 #endif
 
-  // Sweep a single page from the given space conservatively.
-  // Returns the size of the biggest continuous freed memory chunk in bytes.
-  template <SweepingParallelism type>
-  static int SweepConservatively(PagedSpace* space, FreeList* free_list,
-                                 Page* p);
-
   INLINE(static bool ShouldSkipEvacuationSlotRecording(Object** anchor)) {
     return Page::FromAddress(reinterpret_cast<Address>(anchor))
         ->ShouldSkipEvacuationSlotRecording();