IndexedDB: Revert change to enable reuse of leveldb manifest in IDB (take 2).

IndexedDB: Revert change to enable reuse of leveldb manifest in IDB (take 2).

The prior revert (ca6c875) of the leveldb manifest reuse change (de701ab) was
insufficient because there appears to be a bug in leveldb where it fails to
consult the reuse_logs option. So if the Env has a working NewAppendableFile
method then leveldb will always try to reuse it's manifest. Deleting our
version of this function so that the base Env implementation will be called
(which fails forcing no-reuse).

BUG=402980, 395799
Committed: https://crrev.com/617e94e4e3b423579ecebc1c01e07bfbd603694d
Cr-Commit-Position: refs/heads/master@{#311576}

[cmumford, 2015-01-14 21:27:56]

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

[cmumford, 2015-01-14 21:28:33]

PTAL

[jsbell, 2015-01-14 21:29:01]

lgtm

[cmumford, 2015-01-14 22:51:20]

The CQ bit was checked by cmumford@chromium.org

[commit-bot: I haz the power, 2015-01-14 22:51:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/852073002/1

[commit-bot: I haz the power, 2015-01-14 23:54:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-14 23:54:58]

Patchset 1 (id:??) landed as
https://crrev.com/617e94e4e3b423579ecebc1c01e07bfbd603694d
Cr-Commit-Position: refs/heads/master@{#311576}