Runtime checks so that CoreBluetooth only used on >= 10.10

Added runtime checks to BluetoothLowEnergyDeviceMac and
BluetoothDiscoveryManagerMac so that CoreBluetooth, particularly the class
CBCentralManager, is only used if on OS X 10.10 or later.  This is done to
address crbug.com/506287 as well as a previous issue where
CBCentralManager caused a crash on the mac_chromium_rel_ng trybot
(running 10.9.5).

BUG=506287
Committed: https://crrev.com/b53d5d2078793f80b78ee4b6229c22fae731add1
Cr-Commit-Position: refs/heads/master@{#338908}

[krstnmnlsn, 2015-07-09 01:12:00]

Patchset #1 (id:1) has been deleted

[krstnmnlsn, 2015-07-09 01:14:28]

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

[krstnmnlsn, 2015-07-09 01:14:29]

Added checks, and also deleted some code that the checks make extraneous / dead.

[krstnmnlsn, 2015-07-09 01:26:31]

The CQ bit was checked by krstnmnlsn@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-09 01:27:48]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228863002/40001

[commit-bot: I haz the power, 2015-07-09 01:27:50]

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

[commit-bot: I haz the power, 2015-07-09 01:27:51]

Dry run: No L-G-T-M from a valid reviewer yet. Only full committers are
accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[scheib, 2015-07-09 03:26:44]

The CQ bit was checked by scheib@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-07-09 03:27:21]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228863002/60001

[commit-bot: I haz the power, 2015-07-09 08:39:59]

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

[commit-bot: I haz the power, 2015-07-09 08:40:00]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[scheib, 2015-07-09 19:51:23]

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_adapter_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_adapter_mac.mm:120: is_discovering ||
low_energy_discovery_manager_->IsDiscovering();
In many of these checks, perhaps just do a pointer check 
  if (low_energy_discovery_manager_.get())
instead of repeating the OS version logic all over?

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_low_energy_device_mac.mm:205: std::string
BluetoothLowEnergyDeviceMac::GetPeripheralIdentifier(
Add a "// static" comment line above this method.

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h:5: #ifndef
DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DISCOVERY_MANAGER_MAC_H_
Consider adding a static method to this class so that all call sites can check
e.g.  BluetoothLowEnergyDiscoveryManagerMac::IsLowEnergyAvailable() and
centralize the detail of this being OSX >= 10.10 there.

[krstnmnlsn, 2015-07-10 00:59:19]

Patchset #6 (id:110001) has been deleted

[krstnmnlsn, 2015-07-10 00:59:31]

Patchset #6 (id:130001) has been deleted

[krstnmnlsn, 2015-07-10 00:59:32]

Patchset #6 (id:150001) has been deleted

[krstnmnlsn, 2015-07-10 00:59:40]

Patchset #6 (id:170001) has been deleted

[krstnmnlsn, 2015-07-10 00:59:49]

Patchset #5 (id:100001) has been deleted

[krstnmnlsn, 2015-07-10 00:59:57]

Patchset #5 (id:190001) has been deleted

[krstnmnlsn, 2015-07-10 01:33:33]

Patchset #5 (id:210001) has been deleted

[krstnmnlsn, 2015-07-10 17:08:04]

Patchset #5 (id:230001) has been deleted

[krstnmnlsn, 2015-07-10 17:11:21]

Patchset #5 (id:250001) has been deleted

[krstnmnlsn, 2015-07-10 17:17:47]

Updated to address comments and to compile on good old OS X 10.6...

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_adapter_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_adapter_mac.mm:120: is_discovering ||
low_energy_discovery_manager_->IsDiscovering();
On 2015/07/09 19:51:23, scheib wrote:
> In many of these checks, perhaps just do a pointer check 
>   if (low_energy_discovery_manager_.get())
> instead of repeating the OS version logic all over?

Ended up using IsLowEnergyAvailable() as a sort of compromise because it is a
method of BluetoothAdapterMac now.  Did this for the sake of centralizing, but
can switch it to the pointer check if you think that's simpler.

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_low_energy_device_mac.mm:205: std::string
BluetoothLowEnergyDeviceMac::GetPeripheralIdentifier(
On 2015/07/09 19:51:23, scheib wrote:
> Add a "// static" comment line above this method.

Done.

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
File device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h (right):

https://codereview.chromium.org/1228863002/diff/80001/device/bluetooth/blueto...
device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h:5: #ifndef
DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DISCOVERY_MANAGER_MAC_H_
On 2015/07/09 19:51:23, scheib wrote:
> Consider adding a static method to this class so that all call sites can check
> e.g.  BluetoothLowEnergyDiscoveryManagerMac::IsLowEnergyAvailable() and
> centralize the detail of this being OSX >= 10.10 there.

I like this idea a lot.  Added the method to mac adapter because it made the
most sense to me..

[scheib, 2015-07-10 17:48:05]

LGTM with:

https://codereview.chromium.org/1228863002/diff/290001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/290001/device/bluetooth/bluet...
device/bluetooth/bluetooth_low_energy_device_mac.mm:34: // For stability we only
use CoreBluetooth on OS X >= 10.10.  Thus
Can remove this comment (and other locations), as I think the code reads
sufficiently "IsLowEnergyAvailable" and the comment on that method satisfies
those who need details.

[krstnmnlsn, 2015-07-10 18:04:08]

The CQ bit was checked by krstnmnlsn@chromium.org to run a CQ dry run

[krstnmnlsn, 2015-07-10 18:04:09]

The patchset sent to the CQ was uploaded after l-g-t-m from scheib@chromium.org
Link to the patchset: https://codereview.chromium.org/1228863002/#ps310001
(title: "Scheib comments #2")

[commit-bot: I haz the power, 2015-07-10 18:04:46]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228863002/310001

[krstnmnlsn, 2015-07-10 18:08:32]

krstnmnlsn@chromium.org changed reviewers:
+ armansito@chromium.org

[krstnmnlsn, 2015-07-10 18:08:33]

Thanks Scheib.
Hey Arman, here's a patch to address crbug.com/506287 by disabling our LE mac
code if not on Yosemite or later.  Please review when you get a chance!

https://codereview.chromium.org/1228863002/diff/290001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/290001/device/bluetooth/bluet...
device/bluetooth/bluetooth_low_energy_device_mac.mm:34: // For stability we only
use CoreBluetooth on OS X >= 10.10.  Thus
On 2015/07/10 17:48:05, scheib wrote:
> Can remove this comment (and other locations), as I think the code reads
> sufficiently "IsLowEnergyAvailable" and the comment on that method satisfies
> those who need details.

Done.

[commit-bot: I haz the power, 2015-07-10 19:00:56]

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

[commit-bot: I haz the power, 2015-07-10 19:00:57]

Dry run: This issue passed the CQ dry run.

[armansito, 2015-07-15 18:04:59]

lgtm with nits

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_adapter_mac_unittest.mm (left):

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
device/bluetooth/bluetooth_adapter_mac_unittest.mm:33: mock_central_manager_ =
[[MockCentralManager alloc] init];
This is unrelated to this CL but you can replace alloc+init with new in ObjC:
[MockCentralManager new]. This only works with zero argument constructors.

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
device/bluetooth/bluetooth_low_energy_device_mac.mm:23:
CHECK(base::mac::IsOSMountainLionOrLater());
should these be DCHECK? (here and below)

[krstnmnlsn, 2015-07-15 19:36:09]

Thanks Arman!

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_adapter_mac_unittest.mm (left):

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
device/bluetooth/bluetooth_adapter_mac_unittest.mm:33: mock_central_manager_ =
[[MockCentralManager alloc] init];
On 2015/07/15 18:04:59, armansito wrote:
> This is unrelated to this CL but you can replace alloc+init with new in ObjC:
> [MockCentralManager new]. This only works with zero argument constructors.

Yeah, I've heard of that, thought there was a slight preference to use
alloc+init (uncited claim on SO
http://stackoverflow.com/questions/3330963/alloc-init-and-new-in-objective-c).

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
File device/bluetooth/bluetooth_low_energy_device_mac.mm (right):

https://codereview.chromium.org/1228863002/diff/310001/device/bluetooth/bluet...
device/bluetooth/bluetooth_low_energy_device_mac.mm:23:
CHECK(base::mac::IsOSMountainLionOrLater());
On 2015/07/15 18:04:59, armansito wrote:
> should these be DCHECK? (here and below)

Done.

[krstnmnlsn, 2015-07-15 19:36:20]

The CQ bit was checked by krstnmnlsn@chromium.org

[krstnmnlsn, 2015-07-15 19:36:21]

The patchset sent to the CQ was uploaded after l-g-t-m from scheib@chromium.org,
armansito@chromium.org
Link to the patchset: https://codereview.chromium.org/1228863002/#ps330001
(title: "CHECK->DCHECK")

[commit-bot: I haz the power, 2015-07-15 19:40:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228863002/330001

[commit-bot: I haz the power, 2015-07-15 20:42:53]

Committed patchset #8 (id:330001)

[commit-bot: I haz the power, 2015-07-15 20:44:07]

Patchset 8 (id:??) landed as
https://crrev.com/b53d5d2078793f80b78ee4b6229c22fae731add1
Cr-Commit-Position: refs/heads/master@{#338908}