Use the tonic namespace for tonic + resulting build fixes

tonic/dart_builtin.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_BUILTIN_H_
 #define SKY_ENGINE_TONIC_DART_BUILTIN_H_
 
 #include "base/macros.h"
 #include "dart/runtime/include/dart_api.h"
 
-namespace blink {
+namespace tonic {
 
 class DartBuiltin {
  public:
   struct Natives {
     const char* name;
     Dart_NativeFunction function;
     int argument_count;
   };
 
   DartBuiltin(const Natives* natives, size_t count);
   ~DartBuiltin();
 
   Dart_NativeFunction Resolver(Dart_Handle name,
                                int argument_count,
                                bool* auto_setup_scope) const;
 
   const uint8_t* Symbolizer(Dart_NativeFunction native_function) const;
 
   // Helper around Dart_LookupLibrary.
   static Dart_Handle LookupLibrary(const char* name);
 
  private:
   const Natives* natives_;
   size_t count_;
 
   DISALLOW_COPY_AND_ASSIGN(DartBuiltin);
 };
 
-}  // namespace blink
+}  // namespace tonic
 
 #endif  // SKY_ENGINE_TONIC_DART_BUILTIN_H_