Update mojo shell so that --args-for can be used on android

shell/command_line_util.h

+// Copyright 2014 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.
+
+#ifndef SHELL_COMMAND_LINE_UTIL_H_
+#define SHELL_COMMAND_LINE_UTIL_H_
+
+#include "shell/context.h"
+
+namespace mojo {
+namespace shell {
+
+// Apply arguments for an application from a line with the following format:

[sky, 2014/12/17 16:44:05]

WDYT of splitting out the extraction functions so they don't take |context|?
That way you could write a test for them. I'm thinking you keep the functions
you have here, but add additional ones that don't use context.
ApplyApplicationArgs/RunCommandLineApps would could the non-context ones and
apply the results to the context.

[qsr, 2014/12/18 14:21:36]

 I didn't do exactly this, but I refactored this to extract the methods that do
actual work, and added some unit tests, tell me if that's fine with you.

+// '--args-for=application_url arg1 arg2 arg3'
+// This does nothing if the line has not the right format.
+void ApplyApplicationArgs(Context* context, const std::string args);

[sky, 2014/12/17 16:44:05]

const std::string&

[qsr, 2014/12/18 14:21:36]

Done.

+
+// Run all application defined on the command line, using the given context.
+void RunCommandLineApps(Context* context);
+
+}  // namespace shell
+}  // namespace mojo
+
+#endif  // SHELL_COMMAND_LINE_UTIL_H_