[Android WebView] Keep a reference to the exclusive data dir lock file.

[Android WebView] Keep a reference to the exclusive data dir lock file.

RandomAccessFile has a CloseGuard which causes a StrictMode violation
during RandomAccessFile.finalize(), i.e. when a RandomAccessFile is
garbage collected. We sometimes hit this StrictMode violation, meaning
that we sometimes close the corresponding file and its file lock
(because the finalizer also closes the actual file).

Instead of throwing away the reference to the data dir lock file, store
it until process termination to ensure we never unlock the file lock
(and to ensure we don't hit the StrictMode violation).

BUG=647291
Committed: https://crrev.com/7c1c15a67b2a3523ff4380cd7845a96331438326
Cr-Commit-Position: refs/heads/master@{#428994}

[gsennton, 2016-11-01 12:12:57]

gsennton@chromium.org changed reviewers:
+ torne@chromium.org

[gsennton, 2016-11-01 12:12:57]

Tried calling System.gc() 15 times with Thread.sleep(500) after each call from
AwStrictModeTest#testLoadEmptyData - that didn't cause
RandomAccessFile.finalize() to be called :/

[Torne, 2016-11-01 13:48:03]

lgtm

[gsennton, 2016-11-01 13:52:13]

The CQ bit was checked by gsennton@chromium.org

[commit-bot: I haz the power, 2016-11-01 13:52:27]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-01 14:12:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-01 14:15:11]

Description was changed from

==========
[Android WebView] Keep a reference to the exclusive data dir lock file.

RandomAccessFile has a CloseGuard which causes a StrictMode violation
during RandomAccessFile.finalize(), i.e. when a RandomAccessFile is
garbage collected. We sometimes hit this StrictMode violation, meaning
that we sometimes close the corresponding file and its file lock
(because the finalizer also closes the actual file).

Instead of throwing away the reference to the data dir lock file, store
it until process termination to ensure we never unlock the file lock
(and to ensure we don't hit the StrictMode violation).

BUG=647291
==========

to

==========
[Android WebView] Keep a reference to the exclusive data dir lock file.

RandomAccessFile has a CloseGuard which causes a StrictMode violation
during RandomAccessFile.finalize(), i.e. when a RandomAccessFile is
garbage collected. We sometimes hit this StrictMode violation, meaning
that we sometimes close the corresponding file and its file lock
(because the finalizer also closes the actual file).

Instead of throwing away the reference to the data dir lock file, store
it until process termination to ensure we never unlock the file lock
(and to ensure we don't hit the StrictMode violation).

BUG=647291

Committed: https://crrev.com/7c1c15a67b2a3523ff4380cd7845a96331438326
Cr-Commit-Position: refs/heads/master@{#428994}
==========

[commit-bot: I haz the power, 2016-11-01 14:15:12]

Patchset 1 (id:??) landed as
https://crrev.com/7c1c15a67b2a3523ff4380cd7845a96331438326
Cr-Commit-Position: refs/heads/master@{#428994}