Revert "add flag to soften the blow of removing a legacy api for flutter"
Revert "add flag to soften the blow of removing a legacy api for flutter"

This reverts commit 1b935e65d17cd821953f78598181dacd5260e29c.

Reason for revert: Breaking Flutter bot.

Original change's description:
> add flag to soften the blow of removing a legacy api for flutter
> 
> Bug: skia:8350
> Change-Id: I2c4a136be7f20d54e67c5fb77f0f3699eda81851
> Reviewed-on: https://skia-review.googlesource.com/152588
> Reviewed-by: Mike Reed <reed@google.com>

TBR=reed@google.com

Change-Id: Ia6bc6b42b49917aa1a7dfd0b2bf1f2fe8a22cffb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:8350
Reviewed-on: https://skia-review.googlesource.com/152667
Reviewed-by: Jim Van Verth <509afb0bfbb23ecaaf1fb3323209f531b45e75a6@google.com>
Commit-Queue: Jim Van Verth <509afb0bfbb23ecaaf1fb3323209f531b45e75a6@google.com>

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