Fix assert accessing pipeline from initBatchTracker

Marks fPipelineInstalled as true before calling initBatchTracker. The
batch subclass ought to be able to access the newly constructed
pipeline object during its init.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1666813002

Review URL: https://codereview.chromium.org/1666813002
1 file changed