Enable gold threaded link

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 15ff58c70a7718e90aae0a746ab15986090bd939..e061ef33cb2045e6f969f5068491ae6fb53a8f69 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -208,8 +208,7 @@ config("compiler") {
     }
 
     # Linker warnings.
-    if ( fatal_linker_warnings &&
-        !(is_chromeos && current_cpu == "arm") &&
+    if (fatal_linker_warnings && !(is_chromeos && current_cpu == "arm") &&
         !(is_android && use_order_profiling) && !is_mac && !is_ios) {
       # TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
       # TODO(lizeb,pasko): Fix link errors when linking with order_profiling=1
@@ -320,15 +319,14 @@ config("compiler") {
     } else {
       ldflags += [
         "-B$gold_path",
+
         # Experimentation found that using four linking threads
         # saved ~20% of link time.
         # https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
         # Only apply this to the target linker, since the host
         # linker might not be gold, but isn't used much anyway.
-        # TODO(raymes): Disable threading because gold is frequently
-        # crashing on the bots: crbug.com/161942.
-        #"-Wl,--threads",
-        #"-Wl,--thread-count=4",
+        "-Wl,--threads",
+        "-Wl,--thread-count=4",

[Nico, 2016/07/04 21:24:58]

I think we only want to enable this if we're using bundled gold (ie usually not
for builds with the cros tool chain). Is this checked for all already?

[tzik, 2016/07/05 04:05:58]

I think it wasn't. Added a condition to check linux_use_bundled_binutils here.

       ]
     }