Bug 1524683 - Add nsFrameLoaderOwner class; r=nika

Depends on D19727

Differential Revision: https://phabricator.services.mozilla.com/D19728

--HG--
extra : moz-landing-system : lando

dom/base/moz.build

@@ -67,6 +67,7 @@ EXPORTS += [
     'nsDOMTokenList.h',
     'nsFocusManager.h',
     'nsFrameLoader.h',  # Because binding headers include it.
+    'nsFrameLoaderOwner.h',
     'nsFrameMessageManager.h',
     'nsGlobalWindow.h',  # Because binding headers include it.
     'nsGlobalWindowInner.h',  # Because binding headers include it.
@@ -331,6 +332,7 @@ UNIFIED_SOURCES += [
     'nsDOMWindowList.cpp',
     'nsFocusManager.cpp',
     'nsFrameLoader.cpp',
+    'nsFrameLoaderOwner.cpp',
     'nsGlobalWindowCommands.cpp',
     'nsHistory.cpp',
     'nsHTMLContentSerializer.cpp',

dom/base/nsFrameLoaderOwner.cpp

@@ -0,0 +1,18 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "nsFrameLoaderOwner.h"
+#include "nsFrameLoader.h"
+
+already_AddRefed<nsFrameLoader> nsFrameLoaderOwner::GetFrameLoader()
+{
+  return do_AddRef(mFrameLoader);
+}
+
+void nsFrameLoaderOwner::SetFrameLoader(nsFrameLoader* aNewFrameLoader)
+{
+  mFrameLoader = aNewFrameLoader;
+}

dom/base/nsFrameLoaderOwner.h

@@ -0,0 +1,43 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 nsFrameLoaderOwner_h_
+#define nsFrameLoaderOwner_h_
+
+class nsFrameLoader;
+
+// IID for the FrameLoaderOwner interface
+#define NS_FRAMELOADEROWNER_IID                      \
+  {                                                  \
+    0x1b4fd25c, 0x2e57, 0x11e9, {                    \
+      0x9e, 0x5a, 0x5b, 0x86, 0xe9, 0x89, 0xa5, 0xc0 \
+    }                                                \
+  }
+
+// Mixin that handles ownership of nsFrameLoader for Frame elements
+// (XULFrameElement, HTMLI/FrameElement, etc...). Manages information when doing
+// FrameLoader swaps.
+//
+// This class is considered an XPCOM mixin. This means that while we inherit
+// from ISupports in order to be QI'able, we expect the classes that inherit
+// nsFrameLoaderOwner to actually implement ISupports for us.
+class nsFrameLoaderOwner : public nsISupports
+{
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_FRAMELOADEROWNER_IID)
+
+  nsFrameLoaderOwner() = default;
+  already_AddRefed<nsFrameLoader> GetFrameLoader();
+  void SetFrameLoader(nsFrameLoader* aNewFrameLoader);
+protected:
+  virtual ~nsFrameLoaderOwner() = default;
+  RefPtr<nsFrameLoader> mFrameLoader;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsFrameLoaderOwner, NS_FRAMELOADEROWNER_IID)
+
+#endif //nsFrameLoaderOwner_h_