From ef157dd2744c230b9e99f2152a70fed4464fc73d Mon Sep 17 00:00:00 2001
From: Benjamin Smedberg <benjamin@smedbergs.us>
Date: Tue, 14 Feb 2017 09:10:31 -0500
Subject: [PATCH] Bug 1333887 - Hold nsNPAPIPlugin alive for active
 nsNPAPIPluginInstance objects. This should happen through the plugin tag, but
 apparently that isn't always working. r=qdot

--HG--
extra : rebase_source : 79750e208d0d7dad50ee6711491222143618fb8d
---
 dom/plugins/base/nsNPAPIPlugin.cpp       |  2 --
 dom/plugins/base/nsNPAPIPlugin.h         | 11 +++++++----
 dom/plugins/base/nsNPAPIPluginInstance.h |  3 ++-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
index a85b02edcd59..1f2e16867258 100644
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -210,8 +210,6 @@ static void CheckClassInitialized()
   NPN_PLUGIN_LOG(PLUGIN_LOG_NORMAL,("NPN callbacks initialized\n"));
 }
 
-NS_IMPL_ISUPPORTS0(nsNPAPIPlugin)
-
 nsNPAPIPlugin::nsNPAPIPlugin()
 {
   memset((void*)&mPluginFuncs, 0, sizeof(mPluginFuncs));
diff --git a/dom/plugins/base/nsNPAPIPlugin.h b/dom/plugins/base/nsNPAPIPlugin.h
index 5725492a5093..96e630b629cc 100644
--- a/dom/plugins/base/nsNPAPIPlugin.h
+++ b/dom/plugins/base/nsNPAPIPlugin.h
@@ -12,6 +12,7 @@
 
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/PluginLibrary.h"
+#include "mozilla/RefCounted.h"
 
 #if defined(XP_WIN)
 #define NS_NPAPIPLUGIN_CALLBACK(_type, _name) _type (__stdcall * _name)
@@ -24,7 +25,9 @@ typedef NS_NPAPIPLUGIN_CALLBACK(NPError, NP_PLUGININIT) (const NPNetscapeFuncs*
 typedef NS_NPAPIPLUGIN_CALLBACK(NPError, NP_PLUGINUNIXINIT) (const NPNetscapeFuncs* pCallbacks, NPPluginFuncs* fCallbacks);
 typedef NS_NPAPIPLUGIN_CALLBACK(NPError, NP_PLUGINSHUTDOWN) ();
 
-class nsNPAPIPlugin : public nsISupports
+// nsNPAPIPlugin is held alive both by active nsPluginTag instances and
+// by active nsNPAPIPluginInstance.
+class nsNPAPIPlugin final
 {
 private:
   typedef mozilla::PluginLibrary PluginLibrary;
@@ -32,7 +35,7 @@ private:
 public:
   nsNPAPIPlugin();
 
-  NS_DECL_ISUPPORTS
+  NS_INLINE_DECL_REFCOUNTING(nsNPAPIPlugin)
 
   // Constructs and initializes an nsNPAPIPlugin object. A nullptr file path
   // will prevent this from calling NP_Initialize.
@@ -59,8 +62,8 @@ public:
 
   static nsresult RetainStream(NPStream *pstream, nsISupports **aRetainedPeer);
 
-protected:
-  virtual ~nsNPAPIPlugin();
+private:
+  ~nsNPAPIPlugin();
 
   NPPluginFuncs mPluginFuncs;
   PluginLibrary* mLibrary;
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.h b/dom/plugins/base/nsNPAPIPluginInstance.h
index 39a0a7325050..5f0375637570 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.h
+++ b/dom/plugins/base/nsNPAPIPluginInstance.h
@@ -30,6 +30,7 @@ class PluginEventRunnable;
 #include "mozilla/EventForwards.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/PluginLibrary.h"
+#include "mozilla/RefPtr.h"
 #include "mozilla/WeakPtr.h"
 
 class nsPluginStreamListenerPeer; // browser-initiated stream class
@@ -384,7 +385,7 @@ public:
   nsXPIDLCString mFakeURL;
 
 private:
-  nsNPAPIPlugin* mPlugin;
+  RefPtr<nsNPAPIPlugin> mPlugin;
 
   nsTArray<nsNPAPIPluginStreamListener*> mStreamListeners;