Replace OFFSET_OF with offsetof as far as possible.

Replace OFFSET_OF with offsetof as far as possible.

The remaining uses need some non-mechanical work:

  * non-standard-layout type, probably due to mixed access control

  * extended field designators

Committed: https://crrev.com/d4f7bff1ea85376278ab9fba63a59e02ea35c68d
Cr-Commit-Position: refs/heads/master@{#29071}

[Sven Panne, 2015-06-17 08:53:08]

svenpanne@chromium.org changed reviewers:
+ bmeurer@chromium.org

[Benedikt Meurer, 2015-06-17 09:03:22]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-06-17 09:03:23]

lgtm

[commit-bot: I haz the power, 2015-06-17 09:03:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1173343006/20001

[commit-bot: I haz the power, 2015-06-17 09:06:48]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-17 09:07:02]

Patchset 2 (id:??) landed as
https://crrev.com/d4f7bff1ea85376278ab9fba63a59e02ea35c68d
Cr-Commit-Position: refs/heads/master@{#29071}