Use the tonic namespace for tonic + resulting build fixes

tonic/dart_invoke.cc

 // Copyright 2015 The Chromium 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 "tonic/dart_invoke.h"
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "tonic/dart_error.h"
 
-namespace blink {
+namespace tonic {
 
 bool DartInvokeAppField(Dart_Handle target, Dart_Handle name,
                                int number_of_arguments,
                                Dart_Handle* arguments) {
   TRACE_EVENT0("sky", "DartInvoke::DartInvokeAppField");
   return LogIfError(Dart_Invoke(target, name, number_of_arguments, arguments));
 }
 
 bool DartInvokeAppClosure(Dart_Handle closure,
                           int number_of_arguments,
                           Dart_Handle* arguments) {
   TRACE_EVENT0("sky", "DartInvoke::DartInvokeAppClosure");
   return LogIfError(
       Dart_InvokeClosure(closure, number_of_arguments, arguments));
 }
 
-}  // namespace blink
+}  // namespace tonic