[Reland] Correct fixed-position recording for Slimming Paint

Source/core/core.gypi

 {
     'includes': [
         'core_generated.gypi',
     ],
     'variables': {
         # Files for which bindings (.cpp and .h files) will be generated
         'core_idl_files': [
             'animation/Animation.idl',
             'animation/AnimationEffect.idl',
             'animation/AnimationNode.idl',
@@ skipping 1867 matching lines @@
             'paint/ImagePainter.cpp',
             'paint/ImagePainter.h',
             'paint/InlineFlowBoxPainter.cpp',
             'paint/InlineFlowBoxPainter.h',
             'paint/InlinePainter.cpp',
             'paint/InlinePainter.h',
             'paint/InlineTextBoxPainter.cpp',
             'paint/InlineTextBoxPainter.h',
             'paint/LayerClipRecorder.cpp',
             'paint/LayerClipRecorder.h',
+            'paint/LayerFixedPositionRecorder.cpp',
+            'paint/LayerFixedPositionRecorder.h',
             'paint/LayoutObjectDrawingRecorder.h',
             'paint/LineBoxListPainter.cpp',
             'paint/LineBoxListPainter.h',
             'paint/ListItemPainter.cpp',
             'paint/ListItemPainter.h',
             'paint/ListMarkerPainter.cpp',
             'paint/ListMarkerPainter.h',
             'paint/MediaControlsPainter.cpp',
             'paint/MediaControlsPainter.h',
             'paint/MultiColumnSetPainter.cpp',
@@ skipping 1981 matching lines @@
             'paint/LayerClipRecorderTest.cpp',
             'paint/LayoutObjectDrawingRecorderTest.cpp',
             'paint/TextPainterTest.cpp',
             'streams/ReadableStreamReaderTest.cpp',
             'streams/ReadableStreamTest.cpp',
             'testing/PrivateScriptTestTest.cpp',
             'xml/parser/SharedBufferReaderTest.cpp',
         ],
     }
 }