mac: Weakly link against the CoreBluetooth framework. (attempt #2)

mac: Weakly link against the CoreBluetooth framework. (attempt #2)

The first attempt to land this CL failed because there weas a missing import in
device/BUILD.gn.

> mac: Weakly link against the CoreBluetooth framework.
>
> In the OSX 10.10 SDK, CoreBluetooth became a top level framework. Previously,
> it was nested in IOBluetooth. In order for Chrome to run on OSes older than OSX
> 10.10, the top level CoreBluetooth framework must be weakly linked.
>
> BUG=463170
> Committed: https://crrev.com/9fde3e00865650009c7e85fcb7157719372b97a8
> Cr-Commit-Position: refs/heads/master@{#326705}

BUG=463170
TBR=rsesek@chromium.org, keybuk@chromium.org

Committed: https://crrev.com/ceb2fff7aa06959511e021778b11b76704f45429
Cr-Commit-Position: refs/heads/master@{#327065}

[erikchen, 2015-04-27 16:48:35]

The CQ bit was checked by erikchen@chromium.org

[commit-bot: I haz the power, 2015-04-27 16:48:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1056313004/80001

[scheib, 2015-04-27 17:26:14]

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

[scheib, 2015-04-27 17:26:14]

FYI you can re-land the 'same' (or with minor diff) patches from the original
code review issues too, makes it clearer who reviewed them and their content.

[commit-bot: I haz the power, 2015-04-27 17:51:01]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-04-27 17:52:06]

Patchset 5 (id:??) landed as
https://crrev.com/ceb2fff7aa06959511e021778b11b76704f45429
Cr-Commit-Position: refs/heads/master@{#327065}