Remove some flaky expectations for WPT with webfonts

Now that the web font timing issue for WPT in Blink has been fixed
(https://crbug.com/507054), these tests should no longer be flaky.

Update FlagExpectations/disable-blink-features=RootLayerScrolling to
match TestExpectations:
1. The three lines associated with crbug.com/553838 are removed in
   https://crrev.com/c/954044
2. The other lines associated with crbug.com/582836 are removed in
   https://crrev.com/c/962704

Bug: 582836, 507054
Change-Id: I8073e7ca86046a437b67e92a7e552e1666cd5983
Reviewed-on: https://chromium-review.googlesource.com/962705
Commit-Queue: Robert Ma <robertma@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543100}

third_party/WebKit/LayoutTests/FlagExpectations/disable-blink-features=RootLayerScrolling

@@ -1356,17 +1356,6 @@ crbug.com/553838 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftest
 # We paint in an incorrect order when layers are present
 crbug.com/370604 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/flexbox/flexbox-paint-ordering-002.xhtml [ Failure ]
 
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-declaration-15.html [ Failure Pass ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-declaration-16.html [ Failure Pass ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-declaration-17.html [ Failure Pass ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-declaration-18.html [ Failure Pass ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-external-font-face-01.html [ Pass Failure ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-font-face-01.html [ Failure ]
-crbug.com/582836 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/variables/variable-font-face-02.html [ Failure ]
-
-crbug.com/553838 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-break-inside-001a.html [ Failure ]
-crbug.com/553838 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-005a.html [ Failure Pass ]
-crbug.com/553838 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-006.html [ Failure ]
 crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-001.html [ Failure Pass ]
 crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-002.html [ Failure Pass ]
 crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-003.html [ Failure Pass ]