Ensure that ConcurrentGC always increments GC num

ConcurrentGC could end up waiting for a GC type like TrimSpaces()
that does not actually end up incrementing completed_gcs_.
It would erroneously think it was done, leaving gcs_requested_
> gcs_completed_, with no task running to perform the requested
GCs, but further requests getting ignored until the next explicit
or heap-overflow GC.

Make ConcurrentGC() actually perform a GC unless the GC number
was incremented. Add a CHECK in ConcurrentGCTask::Run that can catch
this. (Confirmed because it did catch it before we added the fix.)

Have RequestConcurrentGC() return a bool to indicate whether it
did anything. This makes another CHECK possible, and should
eventually allow us to again sleep() until a GC starts.

Bug: 186592536
Bug: 189150802

Test: Build and boot AOSP
Change-Id: Ib11734a9c87b9f9e19c5a3557eac9024f84cadf3
Merged-In: Ib11734a9c87b9f9e19c5a3557eac9024f84cadf3
(cherry picked from commit 20e77ff50047e62e90b3ce9b7849777ffcd55b0d)

0 files changed, 0 insertions, 0 deletions