Move leak crashing tests to LeakExpectations

third_party/WebKit/LayoutTests/LeakExpectations

Index: third_party/WebKit/LayoutTests/LeakExpectations
diff --git a/third_party/WebKit/LayoutTests/LeakExpectations b/third_party/WebKit/LayoutTests/LeakExpectations
index 1500fd9d299995be1a7c51a213aac2edddc197e4..b6ce6cd775fd03e12c71cb175e3111ce359b5f3f 100644
--- a/third_party/WebKit/LayoutTests/LeakExpectations
+++ b/third_party/WebKit/LayoutTests/LeakExpectations
@@ -140,6 +140,12 @@ crbug.com/672740 virtual/mojo-loading/http/tests/security/mixedContent/websocket
 crbug.com/672740 http/tests/security/mixedContent/websocket/insecure-websocket-in-secure-page-worker.html [ Leak Pass ]
 crbug.com/672740 virtual/mojo-loading/http/tests/security/mixedContent/websocket/insecure-websocket-in-secure-page-worker.html [ Leak Pass ]
 
+# Flaky crashes, but bot build logs do not show the failure, at least as linked by the flakiness
+# board.
+crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-2d-printing.html [ Pass Crash ]
+crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-webgl-printing.html [ Pass Crash ]
+
+
 ###########################################################################
 # WARNING: Memory leaks must be fixed asap. Sheriff is expected to revert #
 # culprit CLs instead of suppressing the leaks. If you have any question, #