SkTime: return timezone information

SkTime: return timezone information; format in ISO-8601

Motivation: PDF/A metadata will need the creation date embedded in it.

Also, GetDateTime returns local time in Win32.  This now behaves the
same as on Unix systems.

BUG=skia:3110
Committed: https://skia.googlesource.com/skia/+/0b9d4118ba4f3f1190c063492894e324c63e8fd8

[hal.canary, 2015-04-24 21:03:19]

The CQ bit was checked by halcanary@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-04-24 21:03:29]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1109593002/20001

[hal.canary, 2015-04-24 21:05:41]

Patchset #2 (id:20001) has been deleted

[hal.canary, 2015-04-24 21:05:49]

The CQ bit was checked by halcanary@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-04-24 21:06:02]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1109593002/40001

[hal.canary, 2015-04-24 21:09:18]

The CQ bit was checked by halcanary@google.com to run a CQ dry run

[commit-bot: I haz the power, 2015-04-24 21:09:30]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1109593002/60001

[hal.canary, 2015-04-24 21:13:27]

halcanary@google.com changed reviewers:
+ reed@google.com

[hal.canary, 2015-04-24 21:13:27]

PTAL

[commit-bot: I haz the power, 2015-04-24 21:14:36]

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

[commit-bot: I haz the power, 2015-04-24 21:14:37]

Dry run: This issue passed the CQ dry run.

[reed1, 2015-04-27 20:49:11]

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h
File include/core/SkTime.h (right):

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h#n...
include/core/SkTime.h:30: int16_t  fTimeZoneMinutes;  // The number of minutes
that GetDateTime()
can we move this before or after fYear, to keep the larger int-types together
(makes it easier to feel good about packing)?

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h#n...
include/core/SkTime.h:32: void toISO8601(SkString* dst);
const?

[hal.canary, 2015-04-28 02:35:30]

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h
File include/core/SkTime.h (right):

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h#n...
include/core/SkTime.h:30: int16_t  fTimeZoneMinutes;  // The number of minutes
that GetDateTime()
On 2015/04/27 20:49:11, reed1 wrote:
> can we move this before or after fYear, to keep the larger int-types together
> (makes it easier to feel good about packing)?
> 

Done.

https://codereview.chromium.org/1109593002/diff/80001/include/core/SkTime.h#n...
include/core/SkTime.h:32: void toISO8601(SkString* dst);
On 2015/04/27 20:49:11, reed1 wrote:
> const?

Done.

[hal.canary, 2015-05-01 11:47:19]

ping

[reed1, 2015-05-01 12:56:15]

lgtm w/ nit : we assign the new field last, but it is stored first (as per my
request). Might make 1% more sense to assign it first.

[hal.canary, 2015-05-01 14:02:01]

The CQ bit was checked by halcanary@google.com

[hal.canary, 2015-05-01 14:02:01]

The patchset sent to the CQ was uploaded after l-g-t-m from reed@google.com
Link to the patchset: https://codereview.chromium.org/1109593002/#ps120001
(title: "reorder assignment")

[commit-bot: I haz the power, 2015-05-01 14:02:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1109593002/120001

[commit-bot: I haz the power, 2015-05-01 14:06:29]

Committed patchset #6 (id:120001) as
https://skia.googlesource.com/skia/+/0b9d4118ba4f3f1190c063492894e324c63e8fd8