The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/432052a061cc99ab4339992c6321999d4d77345a

commit 432052a061cc99ab4339992c6321999d4d77345a
Author: Shuotao Gao <stgao@chromium.org>
Date: Tue May 30 20:54:57 2017

[Findit] Add login/logout section and add xsrf_token for login users.

Main change:
1. Add login/logout section on page header.
2. Add XSRF token for login users.
3. Add a general message dialog to show predefined messages for permission and explanation of heuristic hint score.

Other changes:
1. Updated home page, flake result page, and test/compile result page to trigger the message dialog for permission error.
2. Updated test/compile result page to trigger the message dialog to show explanation of heuristic hint score.

Bug:  727817 , 716280
Change-Id: Ie236aea1d9a212f698326df4e78d86bf171a0b38
Reviewed-on: https://chromium-review.googlesource.com/517966
Commit-Queue: Shuotao Gao <stgao@chromium.org>
Reviewed-by: Chan Li <chanli@chromium.org>

[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/analysis/test/reliable-failures.html
[add] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/auth-login.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/waterfall-frontend.yaml
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/app.yaml
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/main.py
[add] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/app-messages-demo.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/gae_libs/appengine_util.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/build_failure.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/analysis/test/non-reliable-failures.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/gae_libs/handlers/test/base_handler_test.py
[add] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/auth-login-demo.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/handlers/flake/analyze_regression_range.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/gae_libs/http/auth_util.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/flake/dashboard.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/home.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/handlers/flake/check_flake.py
[add] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/handlers/home.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/waterfall/culprit.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/list_analyses.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/handlers/flake/test/check_flake_test.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/third_party/bower.json
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/flake/result.html
[add] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/app-messages.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/ui/elements/findit-app.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/templates/waterfall/compile_failure.html
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/handlers/build_failure.py
[modify] https://crrev.com/432052a061cc99ab4339992c6321999d4d77345a/appengine/findit/gae_libs/handlers/base_handler.py