The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f16b3ac745768029718fbbc7cd288453677e49e8

commit f16b3ac745768029718fbbc7cd288453677e49e8
Author: lethalantidote <lethalantidote@chromium.org>
Date: Mon May 16 19:06:52 2016

Allows client to access auth token from command line specified file.

This change allows the client obtain the auth token from the file specified on
the command line just as the server does. Because the functionality would be
very similar, this was pulled out and placed in the common directory.

This allows the code to move away from a hard-coded auth token, and gives the
developer the freedom to specify the auth token, as one has the power to do now
on the server.

Other changes:
* Moved code from blimp_engine_config_unittest.cc into fake_commandline.cc and
fake_commandline.h to make fake command line functionality accessible to both
client and server code.
* Updated blimp_engine_config_unittest.cc and assignment_source_unittest.cc to
use fake_commandline.cc functionality to create fake command lines.
* Updated blimp_browser_test.cc to use get_client_token:GetClientToken() to
maintain consistency.

BUG= 610398 

Review-Url: https://codereview.chromium.org/1958033003
Cr-Commit-Position: refs/heads/master@{#393890}

[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/client/BUILD.gn
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/client/session/assignment_source.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/client/session/assignment_source.h
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/client/session/assignment_source_unittest.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/common/BUILD.gn
[add] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/common/get_client_token.cc
[add] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/common/get_client_token.h
[add] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/common/switches.cc
[add] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/common/switches.h
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/docs/running.md
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/BUILD.gn
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/app/blimp_engine_config.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/app/blimp_engine_config_unittest.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/app/switches.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/app/switches.h
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/engine/app/ui/blimp_screen_unittest.cc
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/test/BUILD.gn
[modify] https://crrev.com/f16b3ac745768029718fbbc7cd288453677e49e8/blimp/test/browser_tests/blimp_browser_test.cc