import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

dom/filehandle/FileHandleCommon.h

@@ -0,0 +1,73 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileHandleCommon_h
+#define mozilla_dom_FileHandleCommon_h
+
+#include "nscore.h"
+
+#ifdef DEBUG
+#define DEBUGONLY(...)  __VA_ARGS__
+#else
+#define DEBUGONLY(...)  /* nothing */
+#endif
+
+struct PRThread;
+
+namespace mozilla {
+namespace dom {
+
+class RefCountedObject
+{
+public:
+  NS_IMETHOD_(MozExternalRefCountType)
+  AddRef() = 0;
+
+  NS_IMETHOD_(MozExternalRefCountType)
+  Release() = 0;
+
+protected:
+  virtual ~RefCountedObject()
+  { }
+};
+
+class ThreadObject
+{
+  DEBUGONLY(PRThread* mOwningThread;)
+
+public:
+  explicit ThreadObject(DEBUGONLY(PRThread* aOwningThread))
+    DEBUGONLY(: mOwningThread(aOwningThread))
+  { }
+
+  virtual ~ThreadObject()
+  { }
+
+#ifdef DEBUG
+  void
+  AssertIsOnOwningThread() const;
+
+  PRThread*
+  OwningThread() const;
+#else
+  void
+  AssertIsOnOwningThread() const
+  { }
+#endif
+};
+
+class RefCountedThreadObject
+  : public RefCountedObject
+  , public ThreadObject
+{
+public:
+  explicit RefCountedThreadObject(DEBUGONLY(PRThread* aOwningThread))
+    : ThreadObject(DEBUGONLY(aOwningThread))
+  { }
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileHandleCommon_h