Mac: Fix missing focus rings on toolbar, profile, and tab buttons

Mac: Fix missing focus rings on toolbar, profile, and tab buttons

This is a reland of http://crrev.com/1160143010, with some additional tweaks.
It was reverted because it tickled an AppKit crash (crbug.com/504808).
The hope is that the crash won't reappear now that we link with 10.10 SDK.

In 10.7, AppKit introduced new API for drawing focus rings.
This automatic focus ring drawing is automatically enabled for applications linking
with 10.8 sdk or later.
After we link with 10.10 SDK the new style focus ring gets enabled but we get
focus rings with double lines. This is because AppKit thinks the buttons are
bordered (-isBordered is YES) and draws lines inside and outside the borders
that are actually not there due to drawing overrides.

10.6 before: manually drawn, tab close and avatar buttons missing focus rings.
10.6 after: no change.

10.7 before: broken, no focus rings on toolbar, avatar, tab close, new tab buttons.
10.7 after: manually drawn, same as 10.6.

10.8+ before: broken, no focus rings on toolbar, avatar, tab close, new tab buttons.
10.8+ after: drawn by AppKit.

Toolbar.xib changes:
Change the toolbar buttons (back, forward, reload, home, wrench) Focus Ring from
None to Default, to allow the new style focus ring to draw.

BUG=459860, 520471
TBR=rsesek@chromium.org

Review URL: https://codereview.chromium.org/1310183005

Cr-Commit-Position: refs/heads/master@{#345989}
(cherry picked from commit 9c75e3773754cfb242c2819cbfb45bd8b5ddf95f)

Committed: https://chromium.googlesource.com/chromium/src/+/1f9f16be3d521b1aad7ba82af84c473e16936e0a

[Andre, 2015-09-10 03:28:56]

Committed patchset #1 (id:1) manually as
1f9f16be3d521b1aad7ba82af84c473e16936e0a (presubmit successful).