SkQP: make text context outlast gm

Change-Id: Ia8e3b42d1b88d111a3885a7b2ae90c29985a8c10
Reviewed-on: https://skia-review.googlesource.com/c/190672
Reviewed-by: Greg Daniel <egdaniel@google.com>
Cherry-Pick: 70441faaef1d845114f496887177b0f54da8d4ca
Reviewed-on: https://skia-review.googlesource.com/c/191282
Reviewed-by: Hal Canary <halcanary@google.com>
1 file changed