Remove unneeded AddRef in RenderViewTest::SetUp

Remove unneeded AddRef in RenderViewTest::SetUp

The AddRef in RenderViewTest::SetUp is not needed and can lead to leaks
in tests. RenderView takes a reference on itself during initialization
and drops it in RenderWidget::Close (which it inherits & calls directly).

TBR=jam@chromium.org
BUG=357747
Committed: https://crrev.com/c27ac70fabb2f93aeb486b783c170bbaee7f7304
Cr-Commit-Position: refs/heads/master@{#328991}

[nasko, 2015-05-07 23:04:16]

nasko@chromium.org changed reviewers:
+ jam@chromium.org

[nasko, 2015-05-07 23:04:16]

Hey John,
Can you review this CL for me?
Thanks in advance!
Nasko

[nasko, 2015-05-07 23:06:08]

The CredentialManager... test failures are going to be fixed by
https://codereview.chromium.org/1124393003/ (currently in CQ).

[nasko, 2015-05-08 17:44:10]

nasko@chromium.org changed reviewers:
+ lfg@chromium.org

[nasko, 2015-05-08 17:44:10]

Hey Lucas,
Can you review this CL for me? You've been digging into how
RenderView/RenderWidget get cleaned up and wanted to get your review on this.
Thanks in advance!
Nasko

[lfg, 2015-05-08 18:18:10]

On 2015/05/08 17:44:10, nasko wrote:
> Hey Lucas,
> Can you review this CL for me? You've been digging into how
> RenderView/RenderWidget get cleaned up and wanted to get your review on this.
> Thanks in advance!
> Nasko

lgtm

The RenderViewImpl::Create calls RenderViewImpl::Initialize, which already
increments the refcount, and SendCloseMessage() on TearDown() will decrement the
refcount. Everything looks sane!

[nasko, 2015-05-08 18:22:11]

Thanks for the review. I'll move John to TBR, since between lfg@ and myself I
think we are good. 

John, feel free to review it async and let me know if you see any issues we
might have missed.

[nasko, 2015-05-08 18:22:17]

The CQ bit was checked by nasko@chromium.org

[commit-bot: I haz the power, 2015-05-08 18:23:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1135643002/1

[commit-bot: I haz the power, 2015-05-08 18:28:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-08 18:29:13]

Patchset 1 (id:??) landed as
https://crrev.com/c27ac70fabb2f93aeb486b783c170bbaee7f7304
Cr-Commit-Position: refs/heads/master@{#328991}