Cleanups.

runtime/lib/errors.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 
 namespace dart {
 
-DEFINE_FLAG(bool, trace_type_checks, false, "Trace runtime type checks.");
-
 // Allocate and throw a new AssertionError.
 // Arg0: index of the first token of the failed assertion.
 // Arg1: index of the first token after the failed assertion.
 // Return value: none, throws an exception.
 DEFINE_NATIVE_ENTRY(AssertionError_throwNew, 2) {
   // No need to type check the arguments. This function can only be called
   // internally from the VM.
   intptr_t assertion_start =
       Smi::CheckedHandle(arguments->NativeArgAt(0)).Value();
   intptr_t assertion_end =
@@ skipping 97 matching lines @@
   intptr_t line;
   script.GetTokenLocation(error_pos, &line, NULL);
   args.SetAt(2, Smi::Handle(Smi::New(line)));
 
   Exceptions::ThrowByType(Exceptions::kAbstractClassInstantiation, args);
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart