Enable compositing for opaque scrolling content on low DPI screens

third_party/WebKit/Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/KeyframeEffect.idl',
             'animation/EffectModel.idl',
             'animation/AnimationEffectReadOnly.idl',
@@ skipping 4202 matching lines @@
             'page/scrolling/ScrollStateTest.cpp',
             'page/scrolling/SnapCoordinatorTest.cpp',
             'paint/HTMLCanvasPainterTest.cpp',
             'paint/LayerClipRecorderTest.cpp',
             'paint/LayoutObjectDrawingRecorderTest.cpp',
             'paint/NinePieceImageGridTest.cpp',
             'paint/PaintControllerPaintTest.cpp',
             'paint/PaintControllerPaintTest.h',
             'paint/PaintInfoTest.cpp',
             'paint/PaintLayerPainterTest.cpp',
+            'paint/PaintLayerScrollableAreaTest.cpp',
             'paint/PaintPropertyTreeBuilderTest.cpp',
             'paint/StubChromeClientForSPv2.h',
             'paint/SVGInlineTextBoxPainterTest.cpp',
             'paint/TableCellPainterTest.cpp',
             'paint/TextPainterTest.cpp',
             'paint/VideoPainterTest.cpp',
             'streams/ReadableStreamOperationsTest.cpp',
             'streams/ReadableStreamReaderTest.cpp',
             'streams/ReadableStreamTest.cpp',
             'style/ComputedStyleTest.cpp',
             'style/OutlineValueTest.cpp',
             'style/SVGComputedStyleTest.cpp',
             'svg/SVGPathParserTest.cpp',
             'svg/UnsafeSVGAttributeSanitizationTest.cpp',
             'svg/graphics/SVGImageTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'timing/MemoryInfoTest.cpp',
             'timing/PerformanceBaseTest.cpp',
             'timing/PerformanceObserverTest.cpp',
             'workers/WorkerThreadTest.cpp',
             'workers/WorkerThreadTestHelper.h',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }