Revert "Use float colors for blend constant"

This reverts commit 52065473ee15568c24af17584748d53cdaa60e82.

Reason for revert: Typo messed up LCD blending

Original change's description:
> Use float colors for blend constant
> 
> Bug: skia:
> Change-Id: Ie2a4b341a5e7762c3e8031fbd0f0d8b1ebae27f1
> Reviewed-on: https://skia-review.googlesource.com/c/168268
> Commit-Queue: Brian Osman <brianosman@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>

TBR=egdaniel@google.com,mtklein@google.com,bsalomon@google.com,brianosman@google.com

Change-Id: Ieaad5724099e18727296ce312d728a1a9ed45c4b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/c/168362
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
11 files changed