[debugger] fix debug-evaluate wrt shadowed context var.

src/debug/debug-evaluate.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_DEBUG_DEBUG_EVALUATE_H_
 #define V8_DEBUG_DEBUG_EVALUATE_H_
 
 #include "src/frames.h"
 #include "src/objects.h"
 
@@ skipping 56 matching lines @@
     void RecordContextsInChain(Handle<Context>* inner_context,
                                Handle<Context> first, Handle<Context> last);
 
     Handle<JSObject> NewJSObjectWithNullProto();
 
     // Helper function to find or create the arguments object for
     // Runtime_DebugEvaluate.
     void MaterializeArgumentsObject(Handle<JSObject> target,
                                     Handle<JSFunction> function);
 
-    Handle<Context> MaterializeReceiver(Handle<Context> target,
-                                        Handle<JSFunction> function);
+    void MaterializeContextChain(Handle<JSObject> target,
+                                 Handle<Context> context);
+
+    void UpdateContextChainFromMaterializedObject(Handle<JSObject> source,
+                                                  Handle<Context> context);
+
+    Handle<Context> MaterializeReceiver(Handle<Context> parent_context,
+                                        Handle<Context> lookup_context,
+                                        Handle<JSFunction> local_function,
+                                        Handle<JSFunction> global_function,
+                                        bool this_is_non_local);
+
+    MaybeHandle<Object> LoadFromContext(Handle<Context> context,
+                                        Handle<String> name);
+
+    void StoreToContext(Handle<Context> context, Handle<String> name,
+                        Handle<Object> value);
 
     Handle<SharedFunctionInfo> outer_info_;
     Handle<Context> innermost_context_;
     List<ContextChainElement> context_chain_;
+    List<Handle<String> > non_locals_;
     Isolate* isolate_;
     JavaScriptFrame* frame_;
     int inlined_jsframe_index_;
   };
 
   static MaybeHandle<Object> Evaluate(Isolate* isolate,
                                       Handle<SharedFunctionInfo> outer_info,
                                       Handle<Context> context,
                                       Handle<HeapObject> context_extension,
                                       Handle<Object> receiver,
                                       Handle<String> source);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_EVALUATE_H_