When RootLayerScrolling is marked "stable" in runtime_enabled_features.json5, the following three unit tests fail on Linux:
DragControllerTest.DragImageForSelectionClipsChildFrameToViewport
DragControllerTest.DragImageForSelectionClipsChildFrameToViewportWithPageScaleFactor
DragControllerTest.DragImageForSelectionClipsToViewport
The failures look like this:
../../third_party/WebKit/Source/core/page/DragControllerTest.cpp:268: Failure
Expected: expected_selection
Which is: "0,17 30x8"
To be equal to: DragController::ClippedSelection(child_frame)
Which is: "0,10 30x15"
Comment 1 by bugdroid1@chromium.org
, Oct 3 2017