Use the tonic namespace for tonic + resulting build fixes

tonic/dart_class_library.h

 // 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.
 
 #ifndef SKY_ENGINE_TONIC_DART_CLASS_LIBRARY_H_
 #define SKY_ENGINE_TONIC_DART_CLASS_LIBRARY_H_
 
 #include <unordered_map>
 #include "base/macros.h"
 #include "dart/runtime/include/dart_api.h"
 #include "tonic/dart_class_provider.h"
 
-namespace blink {
+namespace tonic {
 struct DartWrapperInfo;
 
 class DartClassLibrary {
  public:
   explicit DartClassLibrary();
   ~DartClassLibrary();
 
   void set_provider(DartClassProvider* provider) { provider_ = provider; }
   Dart_PersistentHandle GetClass(const DartWrapperInfo& info);
 
  private:
   DartClassProvider* provider_;
   std::unordered_map<const DartWrapperInfo*, Dart_PersistentHandle> cache_;
 
   DISALLOW_COPY_AND_ASSIGN(DartClassLibrary);
 };
 
-}  // namespace blink
+}  // namespace tonic
 
 #endif  // SKY_ENGINE_TONIC_DART_CLASS_LIBRARY_H_