Fix chromium build
Fix chromium build

First failure: https://chromium-review.googlesource.com/c/chromium/src/+/1480662
Looks caused by uint vs. int comparison in ASSERT_EQ.

TBR=primiano@google.com
Change-Id: I65977445422e6fda4370aef360c0374124268bcd

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