[Mac][Material Design] Add temporary spinner for Incognito mode.

[Mac][Material Design] Add temporary spinner for Incognito mode.

The tab spinner on the Mac will be replaced by a Material Design version
in a future cl. Until then, we need a white version of the current
spinner so that it's visible on Incognito tabs.

R=cpu@chromium.org
BUG=618778
Review-Url: https://codereview.chromium.org/2092193004
Cr-Commit-Position: refs/heads/master@{#402316}
(cherry picked from commit 58a27fbd45da0a20f536e0607b59c8f1658db0be)

Committed: https://chromium.googlesource.com/chromium/src/+/b8cf4cd0f7039f6c5e991e13d925ad9683664a1d

[shrike, 2016-06-28 23:14:26]

Description was changed from

==========
[Mac][Material Design] Add temporary spinner for Incognito mode.

The tab spinner on the Mac will be replaced by a Material Design version
in a future cl. Until then, we need a white version of the current
spinner so that it's visible on Incognito tabs.

R=cpu@chromium.org
BUG=618778

Review-Url: https://codereview.chromium.org/2092193004
Cr-Commit-Position: refs/heads/master@{#402316}
(cherry picked from commit 58a27fbd45da0a20f536e0607b59c8f1658db0be)
==========

to

==========
[Mac][Material Design] Add temporary spinner for Incognito mode.

The tab spinner on the Mac will be replaced by a Material Design version
in a future cl. Until then, we need a white version of the current
spinner so that it's visible on Incognito tabs.

R=cpu@chromium.org
BUG=618778

Review-Url: https://codereview.chromium.org/2092193004
Cr-Commit-Position: refs/heads/master@{#402316}
(cherry picked from commit 58a27fbd45da0a20f536e0607b59c8f1658db0be)

Committed:
https://chromium.googlesource.com/chromium/src/+/b8cf4cd0f7039f6c5e991e13d925...
==========

[shrike, 2016-06-28 23:14:28]

Committed patchset #1 (id:1) manually as
b8cf4cd0f7039f6c5e991e13d925ad9683664a1d.