Add isolate.clean_isolated_files and use in all related recipes.

scripts/slave/recipes/chromium_trybot.py

 # Copyright 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 re
 
 DEPS = [
   'bot_update',
   'chromium',
   'chromium_tests',
@@ skipping 836 matching lines @@
       # Decide the task priority.
       api.swarming.task_priority = build_to_priority(api.properties)
 
     try:
       api.chromium.runhooks(name='runhooks (with patch)', env=runhooks_env)
     except api.step.StepFailure:
       # As part of deapplying patch we call runhooks without the patch.
       deapply_patch(bot_update_step)
       raise
 
+    if bot_config.get('use_isolate') or has_swarming_tests:
+      api.isolate.clean_isolated_files(api.chromium.output_dir)
+
     compile_targets.extend(api.itertools.chain(
         *[t.compile_targets(api) for t in tests]))
     # Remove duplicate targets.
     compile_targets = sorted(set(compile_targets))
     try:
       api.chromium.compile(compile_targets, name='compile (with patch)')
     except api.step.StepFailure:
       deapply_patch(bot_update_step)
       try:
         api.chromium.compile(
@@ skipping 77 matching lines @@
     tests, bot_update_step = compile_and_return_tests(
         mastername, buildername)
 
   def deapply_patch_fn(failing_tests):
     deapply_patch(bot_update_step)
     compile_targets = list(api.itertools.chain(
         *[t.compile_targets(api) for t in failing_tests]))
     if compile_targets:
       # Remove duplicate targets.
       compile_targets = sorted(set(compile_targets))
+      # Search for *.isolated only if enabled in bot config or if some
+      # swarming test is being recompiled.
+      bot_config = get_bot_config(mastername, buildername)
+      has_failing_swarming_tests = [
+          t for t in failing_tests if t.uses_swarming]
+      if bot_config.get('use_isolate') or has_failing_swarming_tests:
+        api.isolate.clean_isolated_files(api.chromium.output_dir)
       try:
         api.chromium.compile(
             compile_targets, name='compile (without patch)')
       except api.step.StepFailure:
         api.tryserver.set_transient_failure_tryjob_result()
         raise
-      # Search for *.isolated only if enabled in bot config or if some
-      # swarming test is being recompiled.
-      bot_config = get_bot_config(mastername, buildername)
-      has_failing_swarming_tests = [
-          t for t in failing_tests if t.uses_swarming]
       if bot_config.get('use_isolate') or has_failing_swarming_tests:
         api.isolate.find_isolated_tests(api.chromium.output_dir)
 
   return api.test_utils.determine_new_failures(api, tests, deapply_patch_fn)
 
 
 def _sanitize_nonalpha(text):
   return ''.join(c if c.isalnum() else '_' for c in text)
 
 
@@ skipping 470 matching lines @@
         ],
       })
     ) +
     api.override_step_data(
       'analyze',
       api.json.output({'status': 'Found dependency',
                        'targets': ['browser_tests', 'base_unittests'],
                        'build_targets': ['base_unittests']}))
   )