Revert of Sketch SkPMFloat (patchset #15 id:270001 of https://codereview.chromium.org/936633002/)

Reason for revert:
http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu13.10-GCC4.8-Arm7-Release-Android_Neon/builds/2120/steps/build%20most/logs/stdio

Original issue's description:
> Sketch SkPMFloat
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/50d2b3114b3e59dc84811881591bf25b2c1ecb9f

TBR=reed@google.com,msarrett@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/952453004
8 files changed