Do not look for the slot in the ScopeInfo's global range when it's not necessary.

src/debug/debug-frames.cc

 // 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.
 
 #include "src/debug/debug-frames.h"
 
 #include "src/frames-inl.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 162 matching lines @@
             target, handle(scope_info->StackLocalName(i), isolate_))
             .ToHandleChecked();
     frame_->SetExpression(index, *value);
   }
 }
 
 
 bool FrameInspector::ParameterIsShadowedByContextLocal(
     Handle<ScopeInfo> info, Handle<String> parameter_name) {
   VariableMode mode;
-  VariableLocation location;
   InitializationFlag init_flag;
   MaybeAssignedFlag maybe_assigned_flag;
-  return ScopeInfo::ContextSlotIndex(info, parameter_name, &mode, &location,
-                                     &init_flag, &maybe_assigned_flag) != -1;
+  return ScopeInfo::ContextSlotIndex(info, parameter_name, &mode, &init_flag,
+                                     &maybe_assigned_flag) != -1;
 }
 
 
 SaveContext* DebugFrameHelper::FindSavedContextForFrame(
     Isolate* isolate, JavaScriptFrame* frame) {
   SaveContext* save = isolate->save_context();
   while (save != NULL && !save->IsBelowFrame(frame)) {
     save = save->prev();
   }
   DCHECK(save != NULL);
@@ skipping 12 matching lines @@
       if (!frames[i].function()->IsSubjectToDebugging()) continue;
       if (++count == index) return i;
     }
   }
   return -1;
 }
 
 
 }  // namespace internal
 }  // namespace v8