Resolve references to "this" the same way as normal variables

src/runtime/runtime-debug.cc

Index: src/runtime/runtime-debug.cc
diff --git a/src/runtime/runtime-debug.cc b/src/runtime/runtime-debug.cc
index 239f2b2e38f36ab7b30a111ce223a5f362525cb7..591c8650e24b4305f0961a2e87924c377ab35534 100644
--- a/src/runtime/runtime-debug.cc
+++ b/src/runtime/runtime-debug.cc
@@ -1298,16 +1298,21 @@ class ScopeIterator {
       context_ = Handle<Context>();
       return;
     }
-    if (scope_type == ScopeTypeScript) seen_script_scope_ = true;
-    if (nested_scope_chain_.is_empty()) {
-      if (scope_type == ScopeTypeScript) {
-        if (context_->IsScriptContext()) {
-          context_ = Handle<Context>(context_->previous(), isolate_);
-        }
-        CHECK(context_->IsNativeContext());
-      } else {
+    if (scope_type == ScopeTypeScript) {
+      seen_script_scope_ = true;
+      if (context_->IsScriptContext()) {
         context_ = Handle<Context>(context_->previous(), isolate_);
       }
+      if (!nested_scope_chain_.is_empty()) {
+        DCHECK_EQ(nested_scope_chain_.last()->scope_type(), SCRIPT_SCOPE);
+        nested_scope_chain_.RemoveLast();
+        DCHECK(nested_scope_chain_.is_empty());
+      }
+      CHECK(context_->IsNativeContext());
+      return;
+    }
+    if (nested_scope_chain_.is_empty()) {
+      context_ = Handle<Context>(context_->previous(), isolate_);
     } else {
       if (nested_scope_chain_.last()->HasContext()) {
         DCHECK(context_->previous() != NULL);