Revert of Add isSingleComponent bool to getConstantColorComponent (patchset #6 id:100001 of https://codereview.chromium.org/608253002/)

Reason for revert:
Changing some GMs

Original issue's description:
> Add isSingleComponent bool to getConstantColorComponent
>
> Initial step to allowing effects to use/output 1 or 4 color/coverage components. This cl doesn't change any current logic and all effects still assume they are working with 4 components.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/3b8af078281a5a20f951b9fd84f38d92b8f6217b

TBR=joshualitt@chromium.org,bsalomon@google.com,reed@google.com,egdaniel@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/617853003
47 files changed