Wholesale move sky/engine/tonic to tonic

tonic/dart_gc_visitor.h

Index: tonic/dart_gc_visitor.h
diff --git a/tonic/dart_gc_visitor.h b/tonic/dart_gc_visitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..05b09feec30fdc0a8cf489a1852a5c7e6b87f434
--- /dev/null
+++ b/tonic/dart_gc_visitor.h
@@ -0,0 +1,39 @@
+// 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_GC_VISITOR_H_
+#define SKY_ENGINE_TONIC_DART_GC_VISITOR_H_
+
+#include "base/logging.h"
+#include "dart/runtime/include/dart_api.h"
+
+namespace blink {
+class DartGCContext;
+
+class DartGCVisitor {
+ public:
+  explicit DartGCVisitor(DartGCContext* context);
+  ~DartGCVisitor();
+
+  bool have_found_set() const {
+    return !!current_set_;
+  }
+
+  Dart_WeakReferenceSet current_set() const {
+    DCHECK(have_found_set());
+    return current_set_;
+  }
+
+  void AddToSetForRoot(const void* root, Dart_WeakPersistentHandle handle);
+
+ private:
+  DartGCContext* context_;
+  Dart_WeakReferenceSet current_set_;
+
+  DISALLOW_COPY_AND_ASSIGN(DartGCVisitor);
+};
+
+}  // namespace blink
+
+#endif  // SKY_ENGINE_TONIC_DART_GC_VISITOR_H_