Move platform abstraction to base library

src/spaces-inl.h

Index: src/spaces-inl.h
diff --git a/src/spaces-inl.h b/src/spaces-inl.h
index 5f024e4e87eeffd9d961214e661152b67d95976d..d9118c8aa45f5839fcbf15f489e521e7aba3e3f9 100644
--- a/src/spaces-inl.h
+++ b/src/spaces-inl.h
@@ -109,27 +109,27 @@ HeapObject* HeapObjectIterator::FromCurrentPage() {
 #ifdef ENABLE_HEAP_PROTECTION
 
 void MemoryAllocator::Protect(Address start, size_t size) {
-  OS::Protect(start, size);
+  base::OS::Protect(start, size);
 }
 
 
 void MemoryAllocator::Unprotect(Address start,
                                 size_t size,
                                 Executability executable) {
-  OS::Unprotect(start, size, executable);
+  base::OS::Unprotect(start, size, executable);
 }
 
 
 void MemoryAllocator::ProtectChunkFromPage(Page* page) {
   int id = GetChunkId(page);
-  OS::Protect(chunks_[id].address(), chunks_[id].size());
+  base::OS::Protect(chunks_[id].address(), chunks_[id].size());
 }
 
 
 void MemoryAllocator::UnprotectChunkFromPage(Page* page) {
   int id = GetChunkId(page);
-  OS::Unprotect(chunks_[id].address(), chunks_[id].size(),
-                chunks_[id].owner()->executable() == EXECUTABLE);
+  base::OS::Unprotect(chunks_[id].address(), chunks_[id].size(),
+                      chunks_[id].owner()->executable() == EXECUTABLE);
 }
 
 #endif