Disable threads on lld-link trunk bots to see if they hurt build time.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 303 matching lines @@
   if (is_android && is_clang) {
     _rebased_android_toolchain_root =
         rebase_path(android_toolchain_root, root_build_dir)
 
     # Let clang find the linker in the NDK.
     ldflags += [ "--gcc-toolchain=$_rebased_android_toolchain_root" ]
   }
 
   if (is_posix && use_lld && !is_nacl) {
     ldflags += [ "-fuse-ld=lld" ]
+
+    # LLD as of 2016/12/02 seems to behave poorly with multi-threading.
+    # Disable threads on LLD trunk bots to see if they hurt build time.
+    if (llvm_force_head_revision) {
+      ldflags += [ "-Wl,-no-threads" ]
+    }
   } else if (use_gold) {
     ldflags += [ "-fuse-ld=gold" ]
     if (is_android) {
       # Use -mstackrealign due to a bug on ia32 Jelly Bean.
       # See crbug.com/521527
       if (current_cpu == "x86") {
         cflags += [ "-mstackrealign" ]
       }
     } else {
       # On Android, this isn't needed.  gcc in the NDK knows to look next to
@@ skipping 1301 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }