Add isolate.py and friends to inputs in 'isolate' gyp step.

build/isolate.gypi

 # 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 file is meant to be included into a target to provide a rule
 # to "build" .isolate files into a .isolated file.
 #
 # To use this, create a gyp target with the following form:
 # 'conditions': [
 #   ['test_isolation_mode != "noop"', {
@@ skipping 22 matching lines @@
 #
 # The generated .isolated file will be:
 #   <(PRODUCT_DIR)/foo_test.isolated
 
 {
   'rules': [
     {
       'rule_name': 'isolate',
       'extension': 'isolate',
       'inputs': [
+        # Files that are known to be involved in this step.
+        '<(DEPTH)/tools/swarm_client/isolate.py',
+        '<(DEPTH)/tools/swarm_client/isolateserver_archive.py',
+        '<(DEPTH)/tools/swarm_client/run_isolated.py',
+        '<(DEPTH)/tools/swarm_client/run_test_cases.py',
+        '<(DEPTH)/tools/swarm_client/short_expression_finder.py',
+        '<(DEPTH)/tools/swarm_client/trace_inputs.py',
+
         # Disable file tracking by the build driver for now. This means the
         # project must have the proper build-time dependency for their runtime
         # dependency. This improves the runtime of the build driver since it
         # doesn't have to stat() all these files.
         #
         # More importantly, it means that even if a isolate_dependency_tracked
         # file is missing, for example if a file was deleted and the .isolate
         # file was not updated, that won't break the build, especially in the
         # case where foo_tests_run is not built! This should be reenabled once
         # the switch-over to running tests on Swarm is completed.
@@ skipping 37 matching lines @@
         ['test_isolation_fail_on_missing == 0', {
             'action': ['--ignore_broken_items'],
           },
         ],
       ],
 
       'msvs_cygwin_shell': 0,
     },
   ],
 }