Add SkQPAssetManager::iterateDir to find files in a directory.

We can't use SkOSFile::Iter in the Java version of SkQP--it doesn't find
any files. We need to load our assets via the AAssetManager.

Bug: skia:13042
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/521841
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Change-Id: I124020d84a6da69f30f3c0b036e1e47a2bd6ceb1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/523179
Reviewed-by: John Stiles <johnstiles@google.com>
4 files changed