Remove support code that was used to pin asan to an older revision.

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.
 CLANG_REVISION=179138
-# ASan Mac builders are pinned to this revision, see http://crbug.com/170629.
-CLANG_ASAN_MAC_REVISION=${CLANG_REVISION}
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"
 LLVM_BUILD_DIR="${LLVM_DIR}/../llvm-build"
 LLVM_BOOTSTRAP_DIR="${LLVM_DIR}/../llvm-bootstrap"
 CLANG_DIR="${LLVM_DIR}/tools/clang"
 CLANG_TOOLS_EXTRA_DIR="${CLANG_DIR}/tools/extra"
 COMPILER_RT_DIR="${LLVM_DIR}/projects/compiler-rt"
 ANDROID_NDK_DIR="${LLVM_DIR}/../android_tools/ndk"
 STAMP_FILE="${LLVM_BUILD_DIR}/cr_build_revision"
 
 # ${A:-a} returns $A if it's set, a else.
 LLVM_REPO_URL=${LLVM_URL:-https://llvm.org/svn/llvm-project}
 
 # Die if any command dies.
 set -e
 
 OS="$(uname -s)"
 
 # Parse command line options.
 force_local_build=
 mac_only=
 run_tests=
 bootstrap=
 with_android=yes
-# Temporary workaround for http://crbug.com/170629: use older Clang for ASan
-# Mac builders.
-is_asan_mac_builder_hackfix=
 with_tools_extra=
 chrome_tools="plugins"
 
 if [[ "${OS}" = "Darwin" ]]; then
   with_android=
 fi
 
 while [[ $# > 0 ]]; do
   case $1 in
     --bootstrap)
       bootstrap=yes
       ;;
     --force-local-build)
       force_local_build=yes
       ;;
     --mac-only)
       mac_only=yes
       ;;
     --run-tests)
       run_tests=yes
       ;;
     --without-android)
       with_android=
       ;;
-    # Temporary workaround for http://crbug.com/170629 - use older Clang for
-    # ASan Mac builders.
-    --is-asan-mac-builder-hackfix)
-      is_asan_mac_builder_hackfix=yes
-      ;;
     --with-tools-extra)
       with_tools_extra=yes
       ;;
     --with-chrome-tools)
       shift
       if [[ $# == 0 ]]; then
         echo "--with-chrome-tools requires an argument."
         exit 1
       fi
       chrome_tools=$1
       ;;
     --help)
       echo "usage: $0 [--force-local-build] [--mac-only] [--run-tests] "
       echo "--bootstrap: First build clang with CC, then with itself."
       echo "--force-local-build: Don't try to download prebuilt binaries."
       echo "--mac-only: Do initial download only on Mac systems."
       echo "--run-tests: Run tests after building. Only for local builds."
       echo "--without-android: Don't build ASan Android runtime library."
-      echo "--is-asan-mac-builder-hackfix: Use older Clang" \
-           "to build ASan on Mac."
       echo "--with-tools-extra: Also build the clang-tools-extra repository."
       echo "--with-chrome-tools: Select which chrome tools to build." \
            "Defaults to plugins."
       echo "    Example: --with-chrome-tools 'plugins empty-string'"
       echo
       exit 1
       ;;
   esac
   shift
 done
 
-# Are we on a Chrome buildbot running ASan?
-function on_asan_mac_host {
-  if [[ "${OS}" != "Darwin" ]]; then
-    return 1
-  fi
-  HOST="$(hostname -s)"
-  # Old (10.6) Chrome Mac ASan Builder. Kept here till we fully migrate to 10.8
-  if [[ "${HOST}" == "vm633-m1" ]]; then
-    return 0
-  fi
-  # 10.8 Chrome Mac ASan Builder.
-  if [[ "${HOST}" == "vm672-m1" ]]; then
-    return 0
-  fi
-  # Chrome Mac ASan LKGR.
-  if [[ "${HOST}" == "mini11-a1" ]]; then
-    return 0
-  fi
-  # mac_asan trybots. These share machines with the mac_layout bots, so only
-  # pin clang if the slave is used for an _asan build, not for a layout build.
-  if [[ "${PWD}" != *asan* ]]; then
-    return 1
-  fi
-  for num in {600..655}
-  do
-    if [[ "${HOST}" == "vm${num}-m4" ]]; then
-      return 0
-    fi
-  done
-  return 1
-}
-
-# Use older Clang for ASan Mac builds. See http://crbug.com/170629.
-if [[ -n "${is_asan_mac_builder_hackfix}" ]] || on_asan_mac_host; then
-  CLANG_REVISION=${CLANG_ASAN_MAC_REVISION}
-fi
-
 # --mac-only prevents the initial download on non-mac systems, but if clang has
 # already been downloaded in the past, this script keeps it up to date even if
 # --mac-only is passed in and the system isn't a mac. People who don't like this
 # can just delete their third_party/llvm-build directory.
 if [[ -n "$mac_only" ]] && [[ "${OS}" != "Darwin" ]] &&
     [[ ! ( "$GYP_DEFINES" =~ .*(clang|tsan|asan)=1.* ) ]] &&
     ! [[ -d "${LLVM_BUILD_DIR}" ]]; then
   exit 0
 fi
 
@@ skipping 262 matching lines @@
   # Run a few tests.
   PLUGIN_SRC_DIR="${THIS_DIR}/../plugins"
   "${PLUGIN_SRC_DIR}/tests/test.sh" "${LLVM_BUILD_DIR}/Release+Asserts"
   cd "${LLVM_BUILD_DIR}"
   make check-all
   cd -
 fi
 
 # After everything is done, log success for this revision.
 echo "${CLANG_REVISION}" > "${STAMP_FILE}"