[RLS] Rebaseline iframe-scaling-with-scroll and scrollRevealButton

This patch rebaselines two tests for minor rounding differences
that were introduced with root layer scrolling:
fast/overflow/scrollRevealButton.html
fast/frames/iframe-scaling-with-scroll.html

Bug: 417782
Change-Id: Ic76981c6bd28db6d5be71474d961760b13140b93
Reviewed-on: https://chromium-review.googlesource.com/940638Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Philip Rogers (OOO) <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539862}

third_party/WebKit/LayoutTests/TestExpectations

@@ -3385,8 +3385,6 @@ crbug.com/807110 external/wpt/media-source/mediasource-sourcebuffer-mode-timesta
 ################################################################################
 # Root Layer Scrolling expectations
 
-crbug.com/417782 fast/frames/iframe-scaling-with-scroll.html [ Failure ]
-crbug.com/417782 fast/overflow/scrollRevealButton.html [ Failure ]
 crbug.com/417782 [ Android ] fast/scrolling/scrollable-area-overflow-auto-display-none.html [ Failure Pass ]
 crbug.com/417782 [ Android ] fast/scrolling/scrollable-area-overflow-not-set.html [ Failure Crash Pass ]
 crbug.com/417782 [ Win ] http/tests/devtools/editor/text-editor-formatter.js [ Timeout ]