Disable LauncherPageFocusTraversal browser test on all platforms.

Disable LauncherPageFocusTraversal browser test on all platforms.

Was previously disabled on ChromeOS, but appears to be flaky across the
board.

BUG=463456
Committed: https://crrev.com/cc5a873aa82d7b56bdaf2f3160f1ceaca998f202
Cr-Commit-Position: refs/heads/master@{#319385}

[Matt Giuca, 2015-03-06 00:22:58]

mgiuca@chromium.org changed reviewers:
+ tapted@chromium.org

[Dirk Pranke, 2015-03-06 00:25:01]

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

[Dirk Pranke, 2015-03-06 00:25:01]

lgtm :).

[tapted, 2015-03-06 00:26:32]

tapted@chromium.org changed reviewers:
- dpranke@chromium.org

[tapted, 2015-03-06 00:26:32]

lgtm yehhh it makes sense that focus traversal would flake in a non-interactive
test

[Matt Giuca, 2015-03-06 00:28:52]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2015-03-06 00:29:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/985563002/1

[commit-bot: I haz the power, 2015-03-06 01:14:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-06 01:14:56]

Patchset 1 (id:??) landed as
https://crrev.com/cc5a873aa82d7b56bdaf2f3160f1ceaca998f202
Cr-Commit-Position: refs/heads/master@{#319385}