[heap] Make compaction space accept external memory.

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 0b4c7690b2cc82e92d3901ccf1bddf4602f6ed52..9ef81a0ea663b77d61b5bb46c7395a7efaae1377 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -2219,7 +2219,6 @@ FreeSpace* FreeListCategory::PickNodeFromList(int size_in_bytes,
 
 
 void FreeListCategory::Free(FreeSpace* free_space, int size_in_bytes) {
-  DCHECK_LE(FreeList::kSmallListMin, size_in_bytes);
   free_space->set_next(top());
   set_top(free_space);
   if (end_ == NULL) {
@@ -2274,7 +2273,7 @@ int FreeList::Free(Address start, int size_in_bytes) {
   Page* page = Page::FromAddress(start);
 
   // Early return to drop too-small blocks on the floor.
-  if (size_in_bytes < kSmallListMin) {
+  if (size_in_bytes <= kSmallListMin) {
     page->add_non_available_small_blocks(size_in_bytes);
     return size_in_bytes;
   }