Support BGR with DirectWrite.

Support BGR with DirectWrite.

BUG=chromium:468509
Committed: https://skia.googlesource.com/skia/+/12f03121bb76214b71677ac0208d74c3c56c3b1f

[bungeman-skia, 2015-03-19 18:20:19]

bungeman@google.com changed reviewers:
+ mtklein@google.com, reed@google.com

[bungeman-skia, 2015-03-19 18:20:20]

So I'm not sure that this is actually fully correct, in that I'm just reversing
which part of the mask goes to 'b' and 'r'. I'm not entirely sure if
DirectWrite's ClearType is symmetrical, but it probably is. I'll have to run
some more experiments to determine that. For the time being however, this is
probably better than what we're currently doing (which is going to a8 masks).

[bungeman-skia, 2015-03-19 18:20:27]

The CQ bit was checked by bungeman@google.com

[commit-bot: I haz the power, 2015-03-19 18:20:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1018863003/1

[commit-bot: I haz the power, 2015-03-19 18:20:44]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-03-20 00:20 UTC

[reed1, 2015-03-19 20:43:51]

looks very clean!

anyway to test it locally?

[reed1, 2015-03-19 20:44:12]

The CQ bit was unchecked by reed@google.com

[reed1, 2015-03-19 20:44:59]

Can you create a GM that has a tmp surface with BGR stripes, and then draw into
it (and then draw it). At least we could inspect that the stripes look horrible
:)

[reed1, 2015-03-19 20:45:12]

lgtm -- I'm ok if we had such a GM later

[bungeman-skia, 2015-03-19 20:57:08]

On 2015/03/19 20:45:12, reed1 wrote:
> lgtm -- I'm ok if we had such a GM later

Already done. You wrote the current one, the 'surfaceprops' GM. I wrote the one
before that when this was just on device.

[bungeman-skia, 2015-03-19 20:57:15]

The CQ bit was checked by bungeman@google.com

[commit-bot: I haz the power, 2015-03-19 20:57:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1018863003/1

[commit-bot: I haz the power, 2015-03-19 20:57:40]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/12f03121bb76214b71677ac0208d74c3c56c3b1f