From 7bb56107310465fb20ac2acc82e72bb627729b11 Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishearth@gmail.com>
Date: Tue, 4 Apr 2017 11:11:27 -0700
Subject: [PATCH] Bug 1351200 - Part 1: stylo: Allow fetching prefs on servo
 traversal threads; r=froydnj

MozReview-Commit-ID: 7MMWyX1t5CR
---
 modules/libpref/prefapi.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/modules/libpref/prefapi.cpp b/modules/libpref/prefapi.cpp
index 5c05a19a7143..2365222ee6d8 100644
--- a/modules/libpref/prefapi.cpp
+++ b/modules/libpref/prefapi.cpp
@@ -26,6 +26,7 @@
 #include "mozilla/ArenaAllocatorExtensions.h"
 #include "mozilla/Logging.h"
 #include "mozilla/MemoryReporting.h"
+#include "mozilla/ServoStyleSet.h"
 #include "mozilla/dom/PContent.h"
 #include "mozilla/dom/ContentPrefs.h"
 #include "nsQuickSort.h"
@@ -762,7 +763,7 @@ inInitArray(const char* key)
 PrefHashEntry* pref_HashTableLookup(const char *key)
 {
 #ifndef MOZ_B2G
-    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(NS_IsMainThread() || mozilla::ServoStyleSet::IsInServoTraversal());
 #endif
     MOZ_ASSERT((!XRE_IsContentProcess() || gPhase != START),
                "pref access before commandline prefs set");