Use the tonic namespace for tonic + resulting build fixes

tonic/dart_string.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_string.h"
 
 #include "base/logging.h"
 
-namespace blink {
+namespace tonic {
 namespace {
 
 void FinalizeString(void* string_impl) {
   DCHECK(string_impl);
   reinterpret_cast<StringImpl*>(string_impl)->deref();
 }
 
 template <typename CharType>
 String Externalize(Dart_Handle handle, intptr_t length) {
   if (!length)
@@ skipping 34 matching lines @@
   DCHECK(Dart_IsString(handle));
   DCHECK(!Dart_IsExternalString(handle));
   bool is_latin1 = Dart_IsStringLatin1(handle);
   intptr_t length;
   Dart_StringLength(handle, &length);
   if (is_latin1)
     return Externalize<LChar>(handle, length);
   return Externalize<UChar>(handle, length);
 }
 
-}  // namespace blink
+}  // namespace tonic