Remove Picture_DeviceType from SampleApp SampleWindow DeviceType
enumeration.
Use a bool variable to control whether the drawing happens via
MultiPictureDraw.
The MultiPictureDraw mode can be activated by 'M', and title
is updated to contain "<MPD>". Previously the MPD mode was
inaccessible.
This works towards removing backend specific code from
SampleApp and VisualBench with the aim to move the code
to the common SkView framework (SkWindow in particular).
The grand goal is to be able to use command buffer GPU
API and NVPR in these apps.
BUG=skia:4733
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1538343002
Review URL: https://codereview.chromium.org/1538343002
8686a5eeef