Disable flaky smooth-scroll tests

The tests are flaky when run in random order.
Example failures:
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65460
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65456
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65449
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65433
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65431
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65424
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65404
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65373
https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests/65279

BUG=664858
TBR=qyearsley@chromium.org

Change-Id: I9871947f69860d308c4b2765f9e23dabbae3c3d4
Reviewed-on: https://chromium-review.googlesource.com/820100
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523237}

third_party/WebKit/LayoutTests/TestExpectations

@@ -1471,15 +1471,11 @@ crbug.com/421412 [ Mac ] fast/text/international/bdo-bidi-width.html [ Failure ]
 crbug.com/574283 [ Mac ] fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/scroll_customization/fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/fixed-background-in-iframe.html [ Skip ]
-crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/horizontal-smooth-scroll-in-rtl.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/main-thread-scrolling-reason-correctness.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/mousewheel-scroll-interrupted.html [ Skip ]
-crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
 
-crbug.com/665577 virtual/threaded/fast/scroll-behavior/overflow-scroll-animates.html [ Pass Timeout ]
 crbug.com/665577 virtual/threaded/fast/scroll-behavior/overflow-scroll-root-frame-animates.html [ Pass Timeout ]
 crbug.com/665577 virtual/threaded/fast/scroll-behavior/smooth-scroll/mousewheel-scroll.html [ Pass Failure ]
-crbug.com/665577 [ Linux Win ] virtual/threaded/fast/scroll-behavior/smooth-scroll/horizontal-smooth-scroll-in-rtl.html [ Pass Failure ]
 crbug.com/665577 [ Linux Win ] virtual/threaded/fast/scroll-behavior/smooth-scroll/mousewheel-scroll-interrupted.html [ Pass Failure ]
 crbug.com/665577 [ Linux Win ] virtual/threaded/fast/scroll-behavior/smooth-scroll/track-scroll.html [ Pass Failure ]
 
@@ -2715,9 +2711,13 @@ crbug.com/702837 fast/text/aat-morx.html [ Skip ]
 
 crbug.com/688670 media/track/track-cue-rendering-after-controls-removed.html [ Pass Failure ]
 
+crbug.com/664858 virtual/threaded/fast/scroll-behavior/overflow-scroll-animates.html [ Skip ]
+crbug.com/664858 virtual/threaded/fast/scroll-behavior/smooth-scroll/horizontal-smooth-scroll-in-rtl.html [ Skip ]
 crbug.com/664858 virtual/threaded/fast/scroll-behavior/smooth-scroll/main-thread-scrolling-reason-added.html [ Skip ]
+crbug.com/664858 virtual/threaded/fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
+crbug.com/664858 virtual/threaded/fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-vertical-rl-anchors.html [ Skip ]
+crbug.com/664858 virtual/threaded/fast/scroll-behavior/smooth-scroll/scroll-during-selection.html [ Skip ]
 
-crbug.com/684874 virtual/threaded/fast/scroll-behavior/smooth-scroll/scroll-during-selection.html [ Pass Failure ]
 crbug.com/766357 virtual/threaded/fast/scroll-behavior/wheel-and-touch-scroll-use-count.html [ Pass Failure ]
 
 # ====== Random order flaky tests end here ======