1 files changed, 37 insertions, 0 deletions
diff --git a/dom/plugins/ipc/PPluginBackgroundDestroyer.ipdl b/dom/plugins/ipc/PPluginBackgroundDestroyer.ipdl
new file mode 100644
index 000000000..cc8ff558e
--- /dev/null
+++ b/dom/plugins/ipc/PPluginBackgroundDestroyer.ipdl
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: sw=4 ts=8 et :
+ */
+/* 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 protocol PPluginInstance;
+
+namespace mozilla {
+namespace plugins {
+
+/**
+ * This protocol exists to allow us to correctly destroy background
+ * surfaces.  The browser owns the surfaces, but shares a "reference"
+ * with the plugin.  The browser needs to notify the plugin when the
+ * background is going to be destroyed, but it can't rely on the
+ * plugin to destroy it because the plugin may crash at any time.  So
+ * the plugin instance relinquishes destruction of the its old
+ * background to actors of this protocol, which can deal with crashy
+ * corner cases more easily than the instance.
+ */
+protocol PPluginBackgroundDestroyer {
+    manager PPluginInstance;
+
+    // The ctor message for this protocol serves double-duty as
+    // notification that that the background is stale.
+
+parent:
+    async __delete__();
+
+state DESTROYING:
+    recv __delete__;
+};
+
+}  // namespace plugins
+}  // namespace mozilla