From d2842daa2df82f9c613d8f73fb1fc7b31f944749 Mon Sep 17 00:00:00 2001
From: Bobby Holley <bobbyholley@gmail.com>
Date: Thu, 17 Aug 2017 09:24:28 -0700
Subject: [PATCH] Avoid creating a stylo thread pool in e10s parent processes.

MozReview-Commit-ID: LW92yNDKZf4
---
 components/style/gecko/generated/bindings.rs | 3 +++
 components/style/gecko/global_style_data.rs  | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/components/style/gecko/generated/bindings.rs b/components/style/gecko/generated/bindings.rs
index d4b7e94326a..69fbfda33f7 100644
--- a/components/style/gecko/generated/bindings.rs
+++ b/components/style/gecko/generated/bindings.rs
@@ -1568,6 +1568,9 @@ extern "C" {
 extern "C" {
     pub fn Gecko_RegisterNamespace(ns: *mut nsIAtom) -> i32;
 }
+extern "C" {
+    pub fn Gecko_ShouldCreateStyleThreadPool() -> bool;
+}
 extern "C" {
     pub fn Gecko_Construct_Default_nsStyleFont(ptr: *mut nsStyleFont,
                                                pres_context:
diff --git a/components/style/gecko/global_style_data.rs b/components/style/gecko/global_style_data.rs
index f396a4ee451..b5698e02193 100644
--- a/components/style/gecko/global_style_data.rs
+++ b/components/style/gecko/global_style_data.rs
@@ -5,6 +5,7 @@
 //! Global style data
 
 use context::StyleSystemOptions;
+use gecko_bindings::bindings;
 use gecko_bindings::bindings::{Gecko_RegisterProfilerThread, Gecko_UnregisterProfilerThread};
 use gecko_bindings::bindings::Gecko_SetJemallocThreadLocalArena;
 use num_cpus;
@@ -78,7 +79,7 @@ lazy_static! {
             }
         }
 
-        let pool = if num_threads < 1 {
+        let pool = if num_threads < 1 || unsafe { !bindings::Gecko_ShouldCreateStyleThreadPool() } {
             None
         } else {
             let configuration = rayon::Configuration::new()