Inline single test-only call of Scope::LookupThis method

R=littledan@chromium.org

Review URL: https://codereview.chromium.org/1430643003

Cr-Commit-Position: refs/heads/master@{#31644}

src/scopes.h

@@ -386,8 +386,6 @@ class Scope: public ZoneObject {
     return receiver_;
   }
 
-  Variable* LookupThis() { return Lookup(ast_value_factory_->this_string()); }
-
   // TODO(wingo): Add a GLOBAL_SCOPE scope type which will lexically allocate
   // "this" (and no other variable) on the native context.  Script scopes then
   // will not have a "this" declaration.

test/cctest/test-parsing.cc

@@ -1091,7 +1091,8 @@ TEST(ScopeUsesArgumentsSuperThis) {
       if ((source_data[i].expected & THIS) != 0) {
         // Currently the is_used() flag is conservative; all variables in a
         // script scope are marked as used.
-        CHECK(scope->LookupThis()->is_used());
+        CHECK(
+            scope->Lookup(info.ast_value_factory()->this_string())->is_used());
       }
       CHECK_EQ((source_data[i].expected & EVAL) != 0, scope->calls_eval());
     }