Add skia::RefPtr class to wrap ref counted classes from Skia.

cc/skia_refptr.h

+// Copyright 2012 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 CC_SKIA_REFPTR_H_
+#define CC_SKIA_REFPTR_H_
+
+#include "third_party/skia/include/core/SkRefCnt.h"
+
+namespace cc {
+
+template<typename T>
+class SkiaRefPtr {

[jamesr, 2012/11/28 22:20:54]

This doesn't belong in cc/

+ public:
+  SkiaRefPtr()
+      : ptr_(NULL) {
+  }
+
+  SkiaRefPtr(const SkiaRefPtr& other)
+      : ptr_(other.ptr_) {
+    SkSafeRef(ptr_);
+  }
+
+  ~SkiaRefPtr() {
+    clear();
+  }
+
+  SkiaRefPtr& operator=(const SkiaRefPtr& other) {
+    SkRefCnt_SafeAssign(ptr_, other.ptr_);
+    return *this;
+  }
+
+  T* get() const { return ptr_; }
+  T& operator*() const { return *ptr_; }
+  T* operator->() const { return ptr_; }
+
+  void clear() {
+    T* to_unref = ptr_;
+    ptr_ = NULL;
+    SkSafeUnref(to_unref);
+  }
+
+  typedef T* SkiaRefPtr::*unspecified_bool_type;
+  operator unspecified_bool_type() const {
+    return ptr_ ? &SkiaRefPtr::ptr_ : NULL;
+  }
+
+  // Skia objects come with a reference of 1, steal that reference here to
+  // take ownership.
+  static SkiaRefPtr<T> Adopt(T* ptr) {
+    return SkiaRefPtr<T>(ptr);
+  }
+
+ private:
+  T* ptr_;
+
+  // Only let Adopt() create this class from a raw Skia ref-counted
+  // pointer.
+  explicit SkiaRefPtr(T* ptr) : ptr_(ptr) {}
+};
+
+}  // namespace cc
+
+#endif  // CC_SKIA_REFPTR_H_