service: Remove some DCHECKs on writer {un,}registration. am: e18b6f87b5 am: 703b6b50c9 am: 1a7b6f5c40 am: 7e72283ea4
service: Remove some DCHECKs on writer {un,}registration. am: e18b6f87b5 am: 703b6b50c9 am: 1a7b6f5c40 am: 7e72283ea4

Change-Id: I9336fa6bce5a02fa21e2fc0069694ff3f1cf98e0

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto