tree 79345f8bd3f3933cd1944745396558caa7b043a5
parent 99ffe24200d8940ceba20f6fbf8c460f994d3cd1
author scroggo <scroggo@google.com> 1401826371 -0700
committer Commit bot <commit-bot@chromium.org> 1401826371 -0700

Return NULL when building empty LayerRasterizer.

In SkLayerRasterizer::snapshotRasterizer() and ::detachRasterizer(),
if no layers have been added, do not attempt to create an
SkLayerRasterizer. Instead, return NULL.

This fixes an error when running tests on Android.

Update dox to state that NULL may be returned.

Add tests.

R=reed@google.com

Author: scroggo@google.com

Review URL: https://codereview.chromium.org/313653006