Fix webview preloading in zygote.

Fix webview preloading in zygote.

We weren't setting the process type, which is fetched via JNI during
JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
don't actually call any methods of LibraryLoader, which need to be on
the right thread, have a Context, have a CommandLine initialised, and
other setup we can't (or at least, don't currently) do in the zygote.

BUG=

Committed: https://crrev.com/db6be0f685e774c56eef7d03a8ab19736023d8bb
Cr-Commit-Position: refs/heads/master@{#439213}

[Torne, 2016-12-16 16:42:05]

torne@chromium.org changed reviewers:
+ rsesek@chromium.org, tobiasjs@chromium.org

[Torne, 2016-12-16 16:42:06]

This is the change I think will make a difference (this may not be enough
initialisation, but this is definitely required as a minimum, and it's probably
only luck that standalone webview actually works without this).

I haven't compiled or tested this yet, but I'm working on it. Uploading now so
that you can try it yourself if you're in a better position than me (and in case
I have to leave before I'm done).

[Torne, 2016-12-16 18:06:09]

Tested this and it appears to fix the crash on startup. Monochrome works in
multiprocess for me with this patch (plus the fd whitelist fix for the
framework)

[Robert Sesek, 2016-12-16 20:35:31]

LGTM. Verified that this fixes the issue we're seeing.

[Robert Sesek, 2016-12-16 20:59:25]

The CQ bit was checked by rsesek@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-16 21:00:11]

Dry run: 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, 2016-12-16 21:41:22]

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

[commit-bot: I haz the power, 2016-12-16 21:41:25]

Dry run: This issue passed the CQ dry run.

[Robert Sesek, 2016-12-16 21:50:35]

rsesek@chromium.org changed reviewers:
+ sgurun@chromium.org

[Tobias Sargeant, 2016-12-16 22:08:16]

LGTM

[Tobias Sargeant, 2016-12-16 22:08:20]

The CQ bit was checked by tobiasjs@chromium.org

[commit-bot: I haz the power, 2016-12-16 22:09:18]

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, 2016-12-16 22:17:06]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481926100416430, "parent_rev":
"903c721c6be668f508c325ad3bc3dfde8e794db9", "commit_rev":
"752346c6d8df467e4d72101c40af3b615588535c"}

[commit-bot: I haz the power, 2016-12-16 22:17:35]

Description was changed from

==========
Fix webview preloading in zygote.

We weren't setting the process type, which is fetched via JNI during
JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
don't actually call any methods of LibraryLoader, which need to be on
the right thread, have a Context, have a CommandLine initialised, and
other setup we can't (or at least, don't currently) do in the zygote.

BUG=
==========

to

==========
Fix webview preloading in zygote.

We weren't setting the process type, which is fetched via JNI during
JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
don't actually call any methods of LibraryLoader, which need to be on
the right thread, have a Context, have a CommandLine initialised, and
other setup we can't (or at least, don't currently) do in the zygote.

BUG=

Review-Url: https://codereview.chromium.org/2583913002
==========

[commit-bot: I haz the power, 2016-12-16 22:17:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-16 22:19:44]

Description was changed from

==========
Fix webview preloading in zygote.

We weren't setting the process type, which is fetched via JNI during
JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
don't actually call any methods of LibraryLoader, which need to be on
the right thread, have a Context, have a CommandLine initialised, and
other setup we can't (or at least, don't currently) do in the zygote.

BUG=

Review-Url: https://codereview.chromium.org/2583913002
==========

to

==========
Fix webview preloading in zygote.

We weren't setting the process type, which is fetched via JNI during
JNI_OnLoad. Set it by constructing the LibraryLoader singleton, but
don't actually call any methods of LibraryLoader, which need to be on
the right thread, have a Context, have a CommandLine initialised, and
other setup we can't (or at least, don't currently) do in the zygote.

BUG=

Committed: https://crrev.com/db6be0f685e774c56eef7d03a8ab19736023d8bb
Cr-Commit-Position: refs/heads/master@{#439213}
==========

[commit-bot: I haz the power, 2016-12-16 22:19:45]

Patchset 1 (id:??) landed as
https://crrev.com/db6be0f685e774c56eef7d03a8ab19736023d8bb
Cr-Commit-Position: refs/heads/master@{#439213}

[Tobias Sargeant, 2016-12-19 09:40:45]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2586193002/ by tobiasjs@chromium.org.

The reason for reverting is: Realised after the fact that we can't set the
process type because the zygote may spawn renderers for Chrome..