Clear the tile backend textures when drawing DDLs
Clear the tile backend textures when drawing DDLs

It appears that the flutter SKPs don't contain an initial clear so the background can be random noise.

This only appears to be an issue for the Metal backend.

Change-Id: I4f5c823cdb1a0a76c0704d4d48355c3a0ed75d43
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/423316
Reviewed-by: Michael Ludwig <cb1f3dd24de0f0b611b26bc28bec758a551d9b7d@google.com>
Commit-Queue: Robert Phillips <95e8ac5504948c7bf91b22c16a8dbb7ae7c66bfd@google.com>

google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia