Mark more roots.

This is most of the stuff. (Everything that currently exists, though there's
more to come.)

Change-Id: I235a21b006820a027c494374a5b52ffefed89c32
diff --git a/src/indirect_reference_table.h b/src/indirect_reference_table.h
index da5f955..a53983f 100644
--- a/src/indirect_reference_table.h
+++ b/src/indirect_reference_table.h
@@ -17,6 +17,7 @@
 #ifndef ART_SRC_INDIRECT_REFERENCE_TABLE_H_
 #define ART_SRC_INDIRECT_REFERENCE_TABLE_H_
 
+#include "heap.h"
 #include "logging.h"
 
 #include <iosfwd>
@@ -307,6 +308,8 @@
     return iterator(table_, Capacity(), Capacity());
   }
 
+  void VisitRoots(Heap::RootVisitor* visitor, void* arg);
+
  private:
   /*
    * Extract the table index from an indirect reference.