[debugger] remove outdated TODO.

We actually do want to make changes in debug-evaluate stick.

R=jgruber@chromium.org
BUG=v8:6071

Review-Url: https://codereview.chromium.org/2743613002
Cr-Commit-Position: refs/heads/master@{#43688}

src/debug/debug-evaluate.cc

@@ -210,7 +210,6 @@ DebugEvaluate::ContextBuilder::ContextBuilder(Isolate* isolate,
 
 
 void DebugEvaluate::ContextBuilder::UpdateValues() {
-  // TODO(yangguo): remove updating values.
   for (int i = 0; i < context_chain_.length(); i++) {
     ContextChainElement element = context_chain_[i];
     if (!element.materialized_object.is_null()) {