WebP - allow more scales
WebP - allow more scales

We previously artificially restricted to using sample sizes. But there
is no reason to do so. Android's new API allows arbitrary scaling, so
support it.

Change-Id: I15f48f9b27b11f8cabb55e3f79ae6ee5ffd39069
Reviewed-on: https://skia-review.googlesource.com/69600
Reviewed-by: Derek Sollenberger <d9b232705cad36bae5cfccf14f9650bb292e6c71@google.com>
Commit-Queue: Leon Scroggins <995cad867ca30d6399abe011583a53547c8afea1@google.com>

rubenvb/skia,google/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,google/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,rubenvb/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,google/skia,rubenvb/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,rubenvb/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,google/skia,google/skia,Hikari-no-Tenshi/android_external_skia,google/skia