Debugger support to display global variables

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 9118)
+++ runtime/vm/object.h	(working copy)
@@ -1778,6 +1778,7 @@
   int next_ix_;  // Index of next element.
 
   friend class ClassDictionaryIterator;
+  friend class LibraryPrefixIterator;
   DISALLOW_COPY_AND_ASSIGN(DictionaryIterator);
 };
 
@@ -1796,6 +1797,16 @@
 };
 
 
+class LibraryPrefixIterator : public DictionaryIterator {
+ public:
+  explicit LibraryPrefixIterator(const Library& library);
+  RawLibraryPrefix* GetNext();
+ private:
+  void MoveToNext();
+  DISALLOW_COPY_AND_ASSIGN(LibraryPrefixIterator);
+};
+
+
 class Library : public Object {
  public:
   RawString* name() const { return raw_ptr()->name_; }