Clean up comment.

TBR=iposva@chromium.org
Review URL: http://codereview.chromium.org/108003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1850 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mark-compact.h

@@ -175,7 +175,8 @@ class MarkCompactCollector: public AllStatic {
   // Mark the heap roots and all objects reachable from them.
   static void MarkRoots(RootMarkingVisitor* visitor);
 
-  // Mark the symbol table specially.  References to symbols are weak.
+  // Mark the symbol table specially.  References to symbols from the
+  // symbol table are weak.
   static void MarkSymbolTable();
 
   // Mark objects in object groups that have at least one object in the