Build:

https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty%20Leak/builds/1297

unexpected_failures:
vr/requestAnimationFrame_invalidhandle.html
vr/requestAnimationFrame_unregister.html

Relevant lines:
19:07:45.459 24323 worker/0 vr/requestAnimationFrame_invalidhandle.html leaked
19:07:45.459 24323   [24327:24445:0106/190745.268031:2536501198:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://content/shell/renderer/layout_test/frame_interface_registry
19:07:45.459 24323   [24327:24445:0106/190745.268541:2536501705:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://content/shell/renderer/layout_test/interface_registry
19:07:45.459 24323   [24327:24445:0106/190745.270398:2536503561:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://Mojo Helpers
19:07:45.459 24323   [1:1:0106/190745.276206:2536509461:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "content/shell/renderer/layout_test/frame_interface_registry"
19:07:45.459 24323   [1:1:0106/190745.276516:2536509727:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "content/shell/renderer/layout_test/interface_registry"
19:07:45.459 24323   [1:1:0106/190745.276739:2536509939:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "Mojo Helpers"
19:07:45.468 14119 [29/37] vr/requestAnimationFrame_invalidhandle.html failed unexpectedly (leak detected: ({"numberOfLiveDocuments":[1,2],"numberOfLiveNodes":[4,24],"numberOfLiveResources":[0,5],"numberOfLiveSuspendableObjects":[2,3]}))

19:07:46.504 24323 worker/0 vr/requestAnimationFrame_unregister.html leaked
19:07:46.504 24323   Xlib:  extension "RANDR" missing on display ":9".
19:07:46.504 24323   [25327:25512:0106/190746.408983:2537642150:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://content/shell/renderer/layout_test/frame_interface_registry
19:07:46.504 24323   [25327:25512:0106/190746.409106:2537642269:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://content/shell/renderer/layout_test/interface_registry
19:07:46.504 24323   [25327:25512:0106/190746.409698:2537642861:WARNING:url_request_job_manager.cc(90)] Failed to map: layout-test-mojom://Mojo Helpers
19:07:46.504 24323   [1:1:0106/190746.412614:2537645894:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "content/shell/renderer/layout_test/frame_interface_registry"
19:07:46.504 24323   [1:1:0106/190746.412805:2537646022:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "content/shell/renderer/layout_test/interface_registry"
19:07:46.504 24323   [1:1:0106/190746.412906:2537646122:ERROR:mojo_context_state.cc(194)] Failed to fetch source for module "Mojo Helpers"
19:07:46.506 14119 [34/37] vr/requestAnimationFrame_unregister.html failed unexpectedly (leak detected: ({"numberOfLiveDocuments":[1,2],"numberOfLiveNodes":[4,24],"numberOfLiveResources":[0,5],"numberOfLiveSuspendableObjects":[2,3]}))

I suspect https://codereview.chromium.org/2617183002, where both the tests were touched.