Offline By Default

Update the shell to try to run applications from the cache
before trying to download those from the web.

If an application is thus run from the cache, the shell
will asynchronously connect the server to update the
application for the next run, if needed.

BUG=https://github.com/domokit/mojo/issues/363
R=ppi@chromium.org

Review URL: https://codereview.chromium.org/1276073004 .

Cr-Mirrored-From: https://github.com/domokit/mojo
Cr-Mirrored-Commit: d15e3f4b8a536b3b5eb3ae506653dc14d1f48d4a

mojo_test

diff --git a/mojo_test b/mojo_test
index 45cdb0d..8f06f42 100755
--- a/mojo_test
+++ b/mojo_test
@@ -49,6 +49,8 @@
 
 _logger = logging.getLogger()
 
+_CACHE_SERVICE_URL = 'mojo:url_response_disk_cache'
+
 
 def main():
   parser = argparse.ArgumentParser(
@@ -66,6 +68,9 @@
       # We need root to have the stdout of the shell available on the host.
       config.require_root = True
     shell, common_shell_args = shell_arguments.get_shell(config, shell_args)
+    # Tests must be reproducible. Start with an empty cache.
+    common_shell_args.append(
+        "--args-for=%s %s" % (_CACHE_SERVICE_URL, "--clear"))
   except shell_config.ShellConfigurationException as e:
     print e
     return 1