Rename sky/engine/bindings2 to sky/engine/bindings

sky/engine/bindings2/nullable.h

-// Copyright 2014 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_BINDINGS2_NULLABLE_H_
-#define SKY_ENGINE_BINDINGS2_NULLABLE_H_
-
-#include "base/logging.h"
-
-namespace blink {
-
-template <typename T>
-class Nullable {
- public:
-  Nullable() : value_(), is_null_(true) {}
-  Nullable(const T& value) : value_(value), is_null_(false) {}
-  Nullable(const Nullable& other)
-      : value_(other.value_), is_null_(other.is_null_) {}
-
-  Nullable& operator=(const Nullable& other) = default;
-
-  void set(const T& value) {
-    value_ = value;
-    is_null_ = false;
-  }
-
-  const T& get() const {
-    DCHECK(!is_null_);
-    return value_;
-  }
-  T& get() {
-    DCHECK(!is_null_);
-    return value_;
-  }
-
-  bool is_null() const { return is_null_; }
-
-  // See comment in RefPtr.h about what UnspecifiedBoolType is.
-  typedef const T* UnspecifiedBoolType;
-  operator UnspecifiedBoolType() const { return is_null_ ? 0 : &value_; }
-
-  bool operator==(const Nullable& other) const {
-    return (is_null_ && other.is_null_) ||
-           (!is_null_ && !other.is_null_ && value_ == other.value_);
-  }
-
- private:
-  T value_;
-  bool is_null_;
-};
-
-}  // namespace blink
-
-#endif  // SKY_ENGINE_BINDINGS2_NULLABLE_H_