Bug 1049501: Don't let the GMPThread event loop recurse while handling IPDL shutdowns r=bsmedberg

content/media/gmp/GMPVideoEncoderParent.cpp

@@ -72,7 +72,9 @@ GMPVideoEncoderParent::GMPVideoEncoderParent(GMPParent *aPlugin)
 
 GMPVideoEncoderParent::~GMPVideoEncoderParent()
 {
-  mEncodedThread->Shutdown();
+  if (mEncodedThread) {
+    mEncodedThread->Shutdown();
+  }
 }
 
 GMPVideoHostImpl&
@@ -249,6 +251,12 @@ GMPVideoEncoderParent::ActorDestroy(ActorDestroyReason aWhy)
     mCallback->Terminated();
     mCallback = nullptr;
   }
+  // Must be shut down before VideoEncoderDestroyed(), since this can recurse
+  // the GMPThread event loop.  See bug 1049501
+  if (mEncodedThread) {
+    mEncodedThread->Shutdown();
+    mEncodedThread = nullptr;
+  }
   if (mPlugin) {
     // Ignore any return code. It is OK for this to fail without killing the process.
     mPlugin->VideoEncoderDestroyed(this);