Enable reference adoption checks for Blink+skia in Debug builds.

skia/config/sk_ref_cnt_ext_debug.h

Index: skia/config/sk_ref_cnt_ext_debug.h
===================================================================
--- skia/config/sk_ref_cnt_ext_debug.h	(revision 0)
+++ skia/config/sk_ref_cnt_ext_debug.h	(working copy)
@@ -0,0 +1,48 @@
+// Copyright 2013 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 SK_REF_CNT_EXT_DEBUG_H_
+#define SK_REF_CNT_EXT_DEBUG_H_
+
+#ifdef SK_REF_CNT_EXT_RELEASE_H_
+#error Only one SkRefCnt should be used.
+#endif
+
+// Alternate implementation of SkRefCnt for Chromium debug builds
+class SK_API SkRefCnt : public SkRefCntBase {
+public:
+  SkRefCnt() : flags_(0) {}
+  void ref() const { SkASSERT(flags_ != AdoptionRequired_Flag); SkRefCntBase::ref(); }
+  void adopted() const { flags_ |= Adopted_Flag; }
+  void requireAdoption() const { flags_ |= AdoptionRequired_Flag; }
+  void deref() const { SkRefCntBase::unref(); }
+private:
+  enum {
+    Adopted_Flag = 0x1,
+    AdoptionRequired_Flag = 0x2,
+  };
+
+  mutable int flags_;
+};
+
+// Bootstrap for Blink's WTF::RefPtr
+
+namespace WTF {
+  inline void adopted(const SkRefCnt* object) {
+    if (!object)
+      return;
+    object->adopted();
+  }
+  inline void requireAdoption(const SkRefCnt* object) {
+    if (!object)
+      return;
+    object->requireAdoption();
+  }
+};
+
+using WTF::adopted;
+using WTF::requireAdoption;
+
+#endif
+