Fixes a problem with the recovery of contexts in the debugger at closure calls.

runtime/vm/stack_frame.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_STACK_FRAME_H_
 #define VM_STACK_FRAME_H_
 
 #include "vm/allocation.h"
 #include "vm/object.h"
 #include "vm/stub_code.h"
@@ skipping 38 matching lines @@
     return 0;
   }
 
   void set_pc(uword value) {
     *reinterpret_cast<uword*>(sp_ + (kSavedPcSlotFromSp * kWordSize)) = value;
   }
 
   // Visit objects in the frame.
   virtual void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
-  // Print a frame.
-  virtual void Print() const;
+  const char* ToCString() const;
 
   // Check validity of a frame, used for assertion purposes.
   virtual bool IsValid() const;
 
   // Frame type.
   virtual bool IsDartFrame() const {
     ASSERT(IsValid());
     return !(IsEntryFrame() || IsExitFrame() || IsStubFrame());
   }
   virtual bool IsStubFrame() const;
@@ skipping 224 matching lines @@
   uword pc_;
   GrowableArray<DeoptInstr*> deopt_instructions_;
   Array& object_table_;
 
   DISALLOW_COPY_AND_ASSIGN(InlinedFunctionsIterator);
 };
 
 }  // namespace dart
 
 #endif  // VM_STACK_FRAME_H_