Default SK_ANGLE to true on Windows, run angle whenever possible on bots.

Default SK_ANGLE to true on Windows, run angle whenever possible on bots.

nanobench doesn't need an update.  It uses the default for --config,
which includes angle.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/88ec329b580a081d9d56cbcaad0ee46cb941c849

[mtklein_C, 2015-02-25 02:05:44]

mtklein@chromium.org changed reviewers:
+ bsalomon@google.com

[mtklein_C, 2015-02-25 02:05:45]

Here's how to run ANGLE everywhere.  We can tear down the ad-hoc -ANGLE bot
after this lands.

[bsalomon, 2015-02-25 15:34:41]

lgtm

[mtklein, 2015-02-25 15:44:10]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-02-25 15:44:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/946933006/40001

[commit-bot: I haz the power, 2015-02-25 15:56:10]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/88ec329b580a081d9d56cbcaad0ee46cb941c849

[mtklein, 2015-02-25 16:15:08]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/954243002/ by mtklein@google.com.

The reason for reverting is: Needs bot upgrades..

[bsalomon, 2015-02-26 15:56:30]

On 2015/02/25 16:15:08, mtklein wrote:
> A revert of this CL (patchset #3 id:40001) has been created in
> https://codereview.chromium.org/954243002/ by mailto:mtklein@google.com.
> 
> The reason for reverting is: Needs bot upgrades..

Just noting that next time we try this I don't think we should make skia_angle
default to 1 in common_variables.gypi simply because setting that var to 1 is
really only desirable for skia developers and testing.