Update Clang on the ASan Android test runner.

Clang package contains ASan runtime library, which is needed to run the tests.
This is specific to Android (on Linux the runtime is statically linked into
the test binaries).

BUG=160952
Review URL: https://codereview.chromium.org/11819061

git-svn-id: http://src.chromium.org/svn/trunk/src/build@176319 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/buildbot/bb_run_bot.py

@@ -86,7 +86,8 @@ def GetBotStepMap():
 
       # Other waterfalls
       B('asan-builder', std_build_steps, None, None),
-      B('asan-tests', std_test_steps, T(std_tests, ['--asan']), None),
+      B('asan-tests', std_test_steps + ['bb_asan_tests_setup'],
+        T(std_tests, ['--asan']), None),
       B('fyi-builder-dbg',
         ['bb_check_webview_licenses', 'bb_compile', 'bb_compile_experimental',
          'bb_run_findbugs', 'bb_zip_build'], None, None),

android/buildbot/buildbot_functions.sh

@@ -93,6 +93,11 @@ function bb_compile_setup {
   gclient runhooks
 }
 
+function bb_asan_tests_setup {
+  # Download or build the ASan runtime library.
+  ${SRC_ROOT}/tools/clang/scripts/update.sh
+}
+
 # Setup goma.  Used internally to buildbot_functions.sh.
 function bb_setup_goma_internal {
   export GOMA_API_KEY_FILE=${GOMA_DIR}/goma.key