leveldb: Env no longer implicitly syncs dir for all newly created files.

leveldb: Env no longer implicitly syncs dir for all newly created files.

A while back ChromiumEnv was enhanced to sync a directory the first time a
newly created file was written to. This was a speculative change added in an
attempt to resolve database corruptions caused by missing files. Since no
improvements were seen as a result of this change it is now being removed.

Additionally leveldb's implicit contract for WritableFile::Sync() is that it
shall sync the directory if that WritableFile is for a manifest - ChromiumEnv
did not do that.

BUG=417769
Committed: https://crrev.com/62520d739a3b95426082fdf059aa262033e795d7
Cr-Commit-Position: refs/heads/master@{#321904}

[cmumford, 2015-03-23 22:32:35]

cmumford@chromium.org changed reviewers:
+ jsbell@chromium.org

[cmumford, 2015-03-23 22:32:35]

I started creating a Finch experiment for this, but think that with only 6
corruptions/day in Chrome OS stable we just don't have the population size. My
plan is to land this in dev/beta, and keep a close eye on the corruption rates -
reverting if necessary.

[jsbell, 2015-03-23 22:42:46]

lgtm

https://codereview.chromium.org/1022983004/diff/1/third_party/leveldatabase/e...
File third_party/leveldatabase/env_chromium.cc (right):

https://codereview.chromium.org/1022983004/diff/1/third_party/leveldatabase/e...
third_party/leveldatabase/env_chromium.cc:314: else
Nit: Remove else since there's an early return in the if clause.

[cmumford, 2015-03-23 22:51:45]

The CQ bit was checked by cmumford@chromium.org

[cmumford, 2015-03-23 22:51:46]

The patchset sent to the CQ was uploaded after l-g-t-m from jsbell@chromium.org
Link to the patchset: https://codereview.chromium.org/1022983004/#ps20001
(title: "Removed unnecessary "else".")

[commit-bot: I haz the power, 2015-03-23 22:52:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1022983004/20001

[commit-bot: I haz the power, 2015-03-24 00:11:39]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-24 00:12:37]

Patchset 2 (id:??) landed as
https://crrev.com/62520d739a3b95426082fdf059aa262033e795d7
Cr-Commit-Position: refs/heads/master@{#321904}