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

This makes it so if isolate.py is modified, all the foo_tests_run steps are
re-run.

R=csharp@chromium.org
BUG=


Review URL: https://chromiumcodereview.appspot.com/13947028

git-svn-id: http://src.chromium.org/svn/trunk/src/build@193415 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

isolate.gypi

@@ -40,6 +40,14 @@
       '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