Add Crash expectation to offscreencanvas flaky test.

third_party/WebKit/LayoutTests/TestExpectations

Index: third_party/WebKit/LayoutTests/TestExpectations
diff --git a/third_party/WebKit/LayoutTests/TestExpectations b/third_party/WebKit/LayoutTests/TestExpectations
index 7533518c1a5b2011e31965821066b70b03b89dad..b2b35bb836395c925bf502e005874a66fc3cc24d 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations
@@ -2230,8 +2230,8 @@ crbug.com/674468 [ Trusty ] compositing/reflections/nested-reflection-transition
 crbug.com/674720 [ Debug Trusty ] http/tests/loading/preload-img-test.html [ Pass Failure ]
 
 # Added 2016-12-16
-crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-2d-printing.html [ Pass Failure ]
-crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-webgl-printing.html [ Pass Failure ]
+crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-2d-printing.html [ Pass Failure Crash ]
+crbug.com/674858 [ Linux ] virtual/threaded/printing/offscreencanvas-webgl-printing.html [ Pass Failure Crash ]
 crbug.com/674917 http/tests/inspector/search/sources-search-scope-many-projects.html [ Pass Failure ]
 
 # for Skia DEPS roll