InProcessGL: Share MailboxManager per service

InProcessGL: Share MailboxManager per service

The current logic ends up creating a MailboxManager per ContextGroup,
so change this to share the mailbox manager across
InProcessCommandBuffer::Service instances.

This also allows for removing code in Android WebView that deals with
passing around the share group. None of these contexts (child, parent
compositor and video) need client-side share groups since mailbox names
are used.

TBR=tedchoc@chromium.org for content/public

Committed: https://crrev.com/a5be71900477280bd56786b39493a3399b52dfdb
Cr-Commit-Position: refs/heads/master@{#293902}

[no sievers, 2014-09-04 21:03:02]

sievers@chromium.org changed reviewers:
+ boliu@chromium.org, danakj@chromium.org

[no sievers, 2014-09-04 21:03:08]

ptal

https://codereview.chromium.org/540143002/diff/1/webkit/common/gpu/context_pr...
File webkit/common/gpu/context_provider_in_process.cc (left):

https://codereview.chromium.org/540143002/diff/1/webkit/common/gpu/context_pr...
webkit/common/gpu/context_provider_in_process.cc:57: attributes.shareResources =
true;
Let's see what the tests say about this and this can go now too.

[boliu, 2014-09-04 21:29:27]

android_webview lgtm

[no sievers, 2014-09-09 01:19:55]

The CQ bit was checked by sievers@chromium.org

[commit-bot: I haz the power, 2014-09-09 01:20:55]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/sievers@chromium.org/540143002/20001

[commit-bot: I haz the power, 2014-09-09 07:59:34]

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

[commit-bot: I haz the power, 2014-09-09 07:59:35]

Exceeded time limit waiting for builds to trigger.

[boliu, 2014-09-09 08:05:25]

The CQ bit was checked by boliu@chromium.org

[commit-bot: I haz the power, 2014-09-09 08:06:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/sievers@chromium.org/540143002/20001

[commit-bot: I haz the power, 2014-09-09 09:16:38]

Committed patchset #2 (id:20001) as 8f96b92bef506dc308f97516b7976a5a5cc5fa31

[commit-bot: I haz the power, 2014-09-10 03:52:13]

Patchset 2 (id:??) landed as
https://crrev.com/a5be71900477280bd56786b39493a3399b52dfdb
Cr-Commit-Position: refs/heads/master@{#293902}