Address comments from Matthias on previous CL

runtime/vm/debugger.h

 // Copyright (c) 2012, 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 RUNTIME_VM_DEBUGGER_H_
 #define RUNTIME_VM_DEBUGGER_H_
 
 #include "include/dart_tools_api.h"
 
 #include "vm/object.h"
@@ skipping 335 matching lines @@
 
   void PrintContextMismatchError(intptr_t ctx_slot,
                                  intptr_t frame_ctx_level,
                                  intptr_t var_ctx_level);
 
   intptr_t TryIndex();
   void GetPcDescriptors();
   void GetVarDescriptors();
   void GetDescIndices();
 
+  RawObject* GetAsyncContextVariable(const String& name);
   RawObject* GetAsyncStreamControllerStreamAwaiter(const Object& stream);
   RawObject* GetAsyncStreamControllerStream();
   RawObject* GetAsyncCompleterAwaiter(const Object& completer);
   RawObject* GetAsyncCompleter();
   void ExtractTokenPositionFromAsyncClosure();
 
   static const char* KindToCString(Kind kind) {
     switch (kind) {
       case kRegular:
         return "Regular";
@@ skipping 391 matching lines @@
 
   friend class Isolate;
   friend class BreakpointLocation;
   DISALLOW_COPY_AND_ASSIGN(Debugger);
 };
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_DEBUGGER_H_