Re-enable some disabled MacOS Layout Tests

These appear to be no longer crashing now that the surfance
synchronization bug has been fixed on MacOS.

Bug: 846632, 846693
Change-Id: I4ecc748429a6a19d565d88d84db9ad1427a6af48
Reviewed-on: https://chromium-review.googlesource.com/1094978Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566002}

third_party/WebKit/LayoutTests/TestExpectations

@@ -4735,8 +4735,6 @@ crbug.com/846547 fast/webgl/webgl-composite-modes.html [ Pass Failure ]
 crbug.com/846471 http/tests/devtools/coverage/reveal-autoformat.js [ Pass Timeout ]
 crbug.com/846656 [ Linux ] external/wpt/css/selectors/focus-visible-002-manual.html [ Pass Timeout ]
 crbug.com/846631 virtual/service-worker-servicification/http/tests/serviceworker/navigation_preload/navigation-preload-resource-timing.html [ Pass Failure ]
-crbug.com/846632 virtual/threaded/animations/responsive/zoom-responsive-transform-animation-002.html [ Pass Failure Crash Timeout ]
-crbug.com/846693 [ Mac ] virtual/threaded/animations/composited-animation-independent-transform-cancel.html [ Pass Crash Timeout ]
 
 # Sheriff 2018-05-28
 # Merged failing devtools/editor tests.
@@ -4763,7 +4761,6 @@ crbug.com/848799 [ Mac ] http/tests/devtools/coverage/multiple-instances-merge.j
 crbug.com/828962 [ Mac ] fast/webgl/webgl-composite-modes-tabswitching.html [ Pass Timeout ]
 
 # Flakes 2018-06-02
-crbug.com/848006 [ Mac ] virtual/threaded/animations/responsive/zoom-responsive-translate-animation.html [ Crash Failure Pass ]
 crbug.com/841567 fast/scrolling/scrollbar-tickmarks-hittest.html [ Failure Pass ]
 
 # Now that upgrade-insecure-requests enforcing is fixed for redirects, this test will fail while reporting is implemented.