Bug 1373603 - Initialize the mEventTarget after we setup MessageLoop::current() to silence a DCHECK. r=billm

MozReview-Commit-ID: EnMm4uhlfQV

ipc/chromium/src/base/message_loop.cc

@@ -182,11 +182,13 @@ MessageLoop::MessageLoop(Type type, nsIThread* aThread)
 #endif  // OS_WIN
       transient_hang_timeout_(0),
       permanent_hang_timeout_(0),
-      next_sequence_num_(0),
-      mEventTarget(new EventTarget(this)) {
+      next_sequence_num_(0) {
   DCHECK(!current()) << "should only have one message loop per thread";
   get_tls_ptr().Set(this);
 
+  // Must initialize after current() is initialized.
+  mEventTarget = new EventTarget(this);
+
   switch (type_) {
   case TYPE_MOZILLA_PARENT:
     MOZ_RELEASE_ASSERT(!aThread);