Fix downloading of LLVM Gold plugin for the official Chrome.

tools/clang/scripts/update.sh

 #!/usr/bin/env bash
 # Copyright (c) 2012 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.
 
 # This script will check out llvm and clang into third_party/llvm and build it.
 
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
@@ skipping 35 matching lines @@
 if [[ -z "$GYP_DEFINES" ]]; then
   GYP_DEFINES=
 fi
 if [[ -z "$GYP_GENERATORS" ]]; then
   GYP_GENERATORS=
 fi
 if [[ -z "$LLVM_DOWNLOAD_GOLD_PLUGIN" ]]; then
   LLVM_DOWNLOAD_GOLD_PLUGIN=
 fi
 
+OS="$(uname -s)"
+
 if [[ "${OS}" == "Linux" ]] && \
    [[ "$GYP_DEFINES" =~ .*buildtype=Official.* ]] && \
    [[ "$GYP_DEFINES" =~ .*branding=Chrome.* ]] ; then
   # LLVM Gold plugin is required to build with this configuration.
   LLVM_DOWNLOAD_GOLD_PLUGIN=1
 fi
 
 # Die if any command dies, error on undefined variable expansions.
 set -eu
 
 
 if [[ -n ${LLVM_FORCE_HEAD_REVISION:-''} ]]; then
   # Use a real revision number rather than HEAD to make sure that the stamp file
   # logic works.
   CLANG_REVISION=$(svn info "$LLVM_REPO_URL" \
       | grep 'Revision:' | awk '{ printf $2; }')
   PACKAGE_VERSION="${CLANG_REVISION}-0"
 fi
 
-OS="$(uname -s)"
-
 # Parse command line options.
 if_needed=
 force_local_build=
 run_tests=
 bootstrap=
 with_android=yes
 chrome_tools="plugins;blink_gc_plugin"
 gcc_toolchain=
 
 if [[ "${OS}" = "Darwin" ]]; then
@@ skipping 571 matching lines @@
   # Run Chrome tool tests.
   ninja -C "${LLVM_BUILD_DIR}" cr-check-all
 fi
 if [[ -n "$run_tests" ]]; then
   # Run the LLVM and Clang tests.
   ninja -C "${LLVM_BUILD_DIR}" check-all
 fi
 
 # After everything is done, log success for this revision.
 echo "${PACKAGE_VERSION}" > "${STAMP_FILE}"