I get 100% repro on the failure running this:

./out/Debug/cc_unittests --single-process-tests --gtest_filter="AnimationPlayerTest.ToString:LayerTreeHostTilesTestPartialInvalidation.PartialRaster_SingleThread_GpuRaster"

Here's the output:
[==========] Running 2 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 1 test from LayerTreeHostTilesTestPartialInvalidation
[ RUN      ] LayerTreeHostTilesTestPartialInvalidation.PartialRaster_SingleThread_GpuRaster
[       OK ] LayerTreeHostTilesTestPartialInvalidation.PartialRaster_SingleThread_GpuRaster (533 ms)
[----------] 1 test from LayerTreeHostTilesTestPartialInvalidation (533 ms total)

[----------] 1 test from AnimationPlayerTest
[ RUN      ] AnimationPlayerTest.ToString
../../cc/animation/animation_player_unittest.cc:416: Failure
      Expected: "AnimationPlayer{id=2, element_id=(1), animations=[]}"
To be equal to: player_->ToString()
      Which is: "AnimationPlayer{id=3, element_id=(1), animations=[]}"
../../cc/animation/animation_player_unittest.cc:425: Failure
      Expected: "AnimationPlayer{id=2, element_id=(1), animations=[Animation{id=42, " "group=73, target_property_id=1, " "run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
      Which is: "AnimationPlayer{id=2, element_id=(1), animations=[Animation{id=42, group=73, target_property_id=1, run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
To be equal to: player_->ToString()
      Which is: "AnimationPlayer{id=3, element_id=(1), animations=[Animation{id=42, group=73, target_property_id=1, run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
../../cc/animation/animation_player_unittest.cc:435: Failure
      Expected: "AnimationPlayer{id=2, element_id=(1), animations=[Animation{id=42, " "group=73, target_property_id=1, " "run_state=WAITING_FOR_TARGET_AVAILABILITY}, Animation{id=45, group=76, " "target_property_id=5, run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
      Which is: "AnimationPlayer{id=2, element_id=(1), animations=[Animation{id=42, group=73, target_property_id=1, run_state=WAITING_FOR_TARGET_AVAILABILITY}, Animation{id=45, group=76, target_property_id=5, run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
To be equal to: player_->ToString()
      Which is: "AnimationPlayer{id=3, element_id=(1), animations=[Animation{id=42, group=73, target_property_id=1, run_state=WAITING_FOR_TARGET_AVAILABILITY}, Animation{id=45, group=76, target_property_id=5, run_state=WAITING_FOR_TARGET_AVAILABILITY}]}"
[  FAILED  ] AnimationPlayerTest.ToString (1 ms)
[----------] 1 test from AnimationPlayerTest (1 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 2 test cases ran. (534 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] AnimationPlayerTest.ToString

The test however passes if run on its own. The other test is likely changing the id, so we can't really depend on a hard coded id.