Initialize CompositorDependencies in RenderWidget's constructor.

Initialize CompositorDependencies in RenderWidget's constructor.

Previously, this member was assigned ad-hoc during initialization of a
RenderWidget. Since there are different initialization paths for
different kinds of RenderWidgets, this led to some strange-looking code:
for example, the initialization of a frame widget would double-assign
CompositorDependencies.

BUG=none
TBR=mkwst@chromium.org

Committed: https://crrev.com/35d31c110f4005d8d11377a5612f498116a5c6d1
Cr-Commit-Position: refs/heads/master@{#339795}

[dcheng, 2015-07-21 21:46:45]

dcheng@chromium.org changed reviewers:
+ nick@chromium.org

[dcheng, 2015-07-21 21:46:46]

Some cleanup. Comes with bonus variadic templates.

[its_nick_at_chromium_org, 2015-07-21 22:08:04]

ncarter@google.com changed reviewers:
+ ncarter@google.com

[its_nick_at_chromium_org, 2015-07-21 22:08:04]

lgtm

https://codereview.chromium.org/1245863003/diff/1/components/test_runner/web_...
File components/test_runner/web_test_proxy.h (right):

https://codereview.chromium.org/1245863003/diff/1/components/test_runner/web_...
components/test_runner/web_test_proxy.h:305: template <class Base, typename...
Args>
Wat. Actually wait no, that's amazing.

One of these days I should learn C++.

[ncarter (slow), 2015-07-21 22:26:06]

lgtm, from the right account this time

[dcheng, 2015-07-21 23:01:07]

dcheng@chromium.org changed reviewers:
+ mkwst@chromium.org

[dcheng, 2015-07-21 23:01:24]

The CQ bit was checked by dcheng@chromium.org

[dcheng, 2015-07-21 23:01:24]

TBRing mkwst@ for components/test_runner changes.

[commit-bot: I haz the power, 2015-07-21 23:03:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1245863003/1

[commit-bot: I haz the power, 2015-07-22 00:17:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-22 00:19:51]

Patchset 1 (id:??) landed as
https://crrev.com/35d31c110f4005d8d11377a5612f498116a5c6d1
Cr-Commit-Position: refs/heads/master@{#339795}