WebRTC: Add Libfuzzer commit and trybot.

scripts/slave/recipes/webrtc/libfuzzer.py

-# Copyright 2014 The Chromium Authors. All rights reserved.
+# Copyright 2015 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.
 
 from recipe_engine.types import freeze
 
+
 DEPS = [
   'archive',
   'bot_update',
   'chromium',
   'file',
   'recipe_engine/json',
   'recipe_engine/path',
   'recipe_engine/platform',
   'recipe_engine/properties',
   'recipe_engine/python',
   'recipe_engine/raw_io',
   'recipe_engine/step',
+  'webrtc',
 ]
 
 
 BUILDERS = freeze({
-  'chromium.fyi': {
+  'client.webrtc': {
     'builders': {
-      'Libfuzzer Upload Linux': {
-        'chromium_apply_config': [ 'proprietary_codecs' ],
+      'Linux64 Release (Libfuzzer)': {
+        'recipe_config': 'webrtc',
         'chromium_config_kwargs': {
           'BUILD_CONFIG': 'Release',
-          'TARGET_PLATFORM': 'linux',
           'TARGET_BITS': 64,
         },
-        'upload_bucket': 'chromium-browser-libfuzzer',
-        'upload_directory': 'asan',
+        'chromium_apply_config': ['webrtc_libfuzzer'],
+        'bot_type': 'builder',
+        'testing': {'platform': 'linux'},
       },
     },
   },
+  'tryserver.webrtc': {
+    'builders': {
+      'linux_libfuzzer_rel': {
+        'recipe_config': 'webrtc',
+        'chromium_config_kwargs': {
+          'BUILD_CONFIG': 'Release',
+          'TARGET_BITS': 64,
+        },
+        'chromium_apply_config': ['webrtc_libfuzzer'],
+        'bot_type': 'builder',
+        'testing': {'platform': 'linux'},
+      },
+    },
+  },
 })
 
 
 def RunSteps(api):
-  mastername = api.m.properties['mastername']
-  buildername, bot_config = api.chromium.configure_bot(BUILDERS, ['mb'])
+  webrtc = api.webrtc
+  webrtc.apply_bot_config(BUILDERS, webrtc.RECIPE_CONFIGS)
 
-  checkout_results = api.bot_update.ensure_checkout(
-      force=True, patch_root=bot_config.get('root_override'))
-
+  api.webrtc.checkout()
   api.chromium.runhooks()
 
   # checkout llvm
   api.step('checkout llvm',
            [api.path.sep.join(['tools', 'clang', 'scripts', 'update.py']),
             '--force-local-build',
             '--without-android'],
            cwd=api.path['checkout'],
            env={'LLVM_FORCE_HEAD_REVISION': 'YES'})
 
-  api.chromium.run_mb(mastername, buildername, use_goma=False)

[kjellander_chromium, 2015/12/16 22:16:54]

MB is a Chromium specific thing that allows dpranke@ to flip back and forth
between GYP and GN and keeps the bot configs in the source tree at
https://code.google.com/p/chromium/codesearch#chromium/src/tools/mb/mb_config...

We don't use it for WebRTC.

+  api.chromium.run_gn(use_goma=False)
 
   step_result = api.python('calculate targets',
           api.path['depot_tools'].join('gn.py'),
           ['--root=%s' % str(api.path['checkout']),
            'refs',
            str(api.chromium.output_dir),
            '--all',
            '--type=executable',
+           '--args="use_libfuzzer=true is_asan=true"',

[kjellander_chromium, 2015/12/16 22:16:54]

This differs from the libfuzzer recipe. It's actually strange they don't pass
use_libfuzzer=true since their fuzzers are also in a condition in
https://code.google.com/p/chromium/codesearch#chromium/src/BUILD.gn&l=737
similar to our
https://chromium.googlesource.com/external/webrtc/+/master/webrtc/BUILD.gn#283

[kjellander_chromium, 2015/12/16 22:22:08]

Nevermind, it's actually not needed. As long as we pass these into the 'gn gen'
command, they'll be stored in out/Release/args.gn and won't need to passed in
subsequent GN calls, that's why they didn't need it.
Removed in PS#2.

            '--as=output',
-           '//testing/libfuzzer:libfuzzer_main',
+           '//webrtc/test/fuzzers:webrtc_fuzzer_main',
           ],
           stdout=api.raw_io.output())
 
   targets = step_result.stdout.split()
   api.step.active_result.presentation.logs['targets'] = targets
   api.chromium.compile(targets=targets)
 
-  api.archive.clusterfuzz_archive(
-          api.path['slave_build'].join('src', 'out', 'Release'),
-          checkout_results.json.output['properties'],
-          bot_config['upload_bucket'],
-          'libfuzzer',
-          archive_subdir_suffix=bot_config['upload_directory'],
-          gs_acl='public-read')
-
 
 def GenTests(api):
   for test in api.chromium.gen_tests_for_builders(BUILDERS):
     yield (test +
            api.step_data('calculate targets',
                stdout=api.raw_io.output('target1 target2 target3'))
            )