Fixing two layout tests on Android broken by enabling virtual-viewport

Source/web/PageScaleConstraintsSet.cpp

Index: Source/web/PageScaleConstraintsSet.cpp
diff --git a/Source/web/PageScaleConstraintsSet.cpp b/Source/web/PageScaleConstraintsSet.cpp
index ebb42ad6bf2d33161e95de6df182eb7cc6157da9..113517d557b0ac4c2f8c4c8e8b1ca9d7e95869d7 100644
--- a/Source/web/PageScaleConstraintsSet.cpp
+++ b/Source/web/PageScaleConstraintsSet.cpp
@@ -150,6 +150,12 @@ IntSize PageScaleConstraintsSet::mainFrameSize(int contentWidthIncludingScrollba
         && m_userAgentConstraints.minimumScale < finalConstraints().minimumScale
         && contentWidthIncludingScrollbar
         && m_viewSize.width()) {
+
+        // Special case where the contents are exactly as wide as the viewport to prevent an off-by-one due
+        // to floating point imprecision in the aspect ratio height calculation.
+        if (contentWidthIncludingScrollbar == m_viewSize.width())
+            return m_viewSize;
+
         return expandedIntSize(FloatSize(
             contentWidthIncludingScrollbar,
             computeHeightByAspectRatio(contentWidthIncludingScrollbar, m_viewSize)));