Add a close box to flights-app toast.

Add a close box to flights-app toast.

This is to get a case of having an outline on an
absolutely positioned, overflow:hidden, i.e. a
self-painting layer.

TBR=esprehn@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/ffcbc3b2f5417b09328eae4aeb8de2e5eab6324d

[ojan, 2015-01-27 06:54:44]

Committed patchset #2 (id:20001) manually as
ffcbc3b2f5417b09328eae4aeb8de2e5eab6324d (presubmit successful).

[abarth-chromium, 2015-01-27 06:58:06]

abarth@chromium.org changed reviewers:
+ abarth@chromium.org

[abarth-chromium, 2015-01-27 06:58:06]

lgtm

[blundell, 2015-01-27 09:30:15]

blundell@chromium.org changed reviewers:
+ blundell@chromium.org

[blundell, 2015-01-27 09:30:16]

FYI, I reverted this CL in https://codereview.chromium.org/880863002:

    This test broke sky_tests:
    
    Regressions: Unexpected text-only failures (6)
      framework/flights-app.sky [ Failure ]
    
    Example:
    
   
http://build.chromium.org/p/client.mojo/builders/Mojo%20Linux%20ASan%20%28dbg...