Rename function in PathOpsExtendedTest which takes strings.
Rename function in PathOpsExtendedTest which takes strings.

A few methods in PathOpsExtendedTest were changed to write to SkStrings
instead of SkStreams. However, the names of these functions confusingly
still have "Stream" in their names. This CL is just a static function
rename and some small clean-up.

Change-Id: Idf21b2aba28a2f984ef30cb5c18e26a43a9c7201
Reviewed-on: https://skia-review.googlesource.com/6819
Reviewed-by: Cary Clark <52792aa984ff6c4e9c802c7fa3093ed6a52a791f@google.com>
Commit-Queue: Ben Wagner <53965154ffeecc4a10886eab9259e95965f2979a@google.com>

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