fLuminance is unsed unless SK_GAMMA_APPLY_TO_A8 is defined

fLuminance is unsed unless SK_GAMMA_APPLY_TO_A8 is defined

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/50282b4390dcddcf3b1d51631c0133045ae1f233

[mtklein, 2015-01-22 03:06:42]

mtklein@google.com changed reviewers:
+ jvanverth@google.com, mtklein@google.com

[mtklein, 2015-01-22 03:06:54]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-01-22 03:07:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865103002/1

[commit-bot: I haz the power, 2015-01-22 03:07:07]

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 2015-01-22 09:07 UTC

[commit-bot: I haz the power, 2015-01-22 09:07:06]

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

[commit-bot: I haz the power, 2015-01-22 09:07:07]

No LGTM from a valid reviewer yet. Please ask for an LGTM from a
full Skia committer from
https://skia.googlesource.com/skia/+/master/CQ_COMMITTERS

[jvanverth1, 2015-01-22 15:56:25]

lgtm

[mtklein, 2015-01-22 15:59:16]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2015-01-22 15:59:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865103002/1

[commit-bot: I haz the power, 2015-01-22 15:59:55]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/50282b4390dcddcf3b1d51631c0133045ae1f233