Do not throw away the savelayer if kDontClipToLayer_PrivateSaveLayerFlag is set

This affects the Android CTS test
android.uirendering.cts.testclasses.LayerTests#testSaveLayerUnclippedWithAlpha

BUG=skia:

Change-Id: Idae150e7e4f7ed9a1a225c382ba0b40d3f840937
Reviewed-on: https://skia-review.googlesource.com/8892
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Yuqian Li <liyuqian@google.com>
2 files changed