Switch tab.cc to use an empty border for the contents.

Switch tab.cc to use an empty border for the contents.

This is a small code simplification.

Also clean up border.cc a bit -- use gfx::Insets more consistently, make the
class naming (SolidSidedBorder) match the function naming
(CreateSolidSidedBorder()), and be consistent about whether or not to inline
class methods.

BUG=none
TEST=none

Committed: https://crrev.com/6322a36ae3aa51c4ec9537486c6c3bae5427c545
Cr-Commit-Position: refs/heads/master@{#353918}

[Peter Kasting, 2015-10-13 21:37:22]

pkasting@chromium.org changed reviewers:
+ sky@chromium.org

[sky, 2015-10-13 21:52:17]

LGTM

[Peter Kasting, 2015-10-13 21:53:23]

The CQ bit was checked by pkasting@chromium.org

[commit-bot: I haz the power, 2015-10-13 21:55:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1401933004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1401933004/1

[commit-bot: I haz the power, 2015-10-13 22:43:47]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-10-13 22:43:48]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Peter Kasting, 2015-10-13 23:19:00]

The CQ bit was checked by pkasting@chromium.org

[Peter Kasting, 2015-10-13 23:19:00]

The patchset sent to the CQ was uploaded after l-g-t-m from sky@chromium.org
Link to the patchset: https://codereview.chromium.org/1401933004/#ps20001
(title: "Fix test")

[commit-bot: I haz the power, 2015-10-13 23:20:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1401933004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1401933004/20001

[commit-bot: I haz the power, 2015-10-14 00:09:40]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-14 00:10:31]

Patchset 2 (id:??) landed as
https://crrev.com/6322a36ae3aa51c4ec9537486c6c3bae5427c545
Cr-Commit-Position: refs/heads/master@{#353918}