Get rid of distinction between below- and above-watermark in page allocation....

src/incremental-marking.cc

Index: src/incremental-marking.cc
===================================================================
--- src/incremental-marking.cc	(revision 7216)
+++ src/incremental-marking.cc	(working copy)
@@ -87,7 +87,7 @@
 
 
 static void ClearMarkbits(PagedSpace* space) {
-  PageIterator it(space, PageIterator::PAGES_IN_USE);
+  PageIterator it(space);
 
   while (it.has_next()) {
     Page* p = it.next();
@@ -97,16 +97,18 @@
 
 
 static void ClearMarkbits() {
-  // We are sweeping code and map spaces precisely so clearing is not required.
+  // TODO: Clear the mark bits in the sweeper.
   ClearMarkbits(Heap::old_pointer_space());
   ClearMarkbits(Heap::old_data_space());
   ClearMarkbits(Heap::cell_space());
+  ClearMarkbits(Heap::map_space());
+  ClearMarkbits(Heap::code_space());
 }
 
 
 #ifdef DEBUG
   static void VerifyMarkbitsAreClean(PagedSpace* space) {
-    PageIterator it(space, PageIterator::PAGES_IN_USE);
+    PageIterator it(space);
 
     while (it.has_next()) {
       Page* p = it.next();