Support both old and new MANIFEST.json formats, and update baselines.

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 d2d5d23d98fcea291fb5e086c395ca464eba3ece..e17a887a87ed97cf9ebb610d9f82b00632306bd0 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations
@@ -1661,7 +1661,9 @@ crbug.com/600248 imported/wpt/web-animations/interfaces/Animation/finished.html
 crbug.com/600248 imported/wpt/web-animations/interfaces/Animation/oncancel.html [ Pass Failure ]
 crbug.com/600248 imported/wpt/web-animations/interfaces/Animation/onfinish.html [ Pass Failure ]
 crbug.com/600248 imported/wpt/web-animations/interfaces/Animation/playbackRate.html [ Pass Failure ]
-
+# This test may either fail a DCHECK or time out:
+# https://storage.googleapis.com/chromium-layout-test-archives/mac_chromium_rel_ng/364861/layout-test-results/results.html
+crbug.com/600248 imported/wpt/web-animations/interfaces/Animation/cancel.html [ Crash Timeout ]
 crbug.com/600248 imported/wpt/web-animations/timing-model/animations/updating-the-finished-state.html [ Pass Failure Timeout ]
 
 crbug.com/611658 [ Win7 ] fast/forms/text/text-font-height-mismatch.html [ Failure ]