positionForPlatform  569 Source/core/editing/FrameSelection.cpp     return positionForPlatform(true);
positionForPlatform  574 Source/core/editing/FrameSelection.cpp     return positionForPlatform(false);
positionForPlatform  215 Source/core/editing/FrameSelection.h     VisiblePosition positionForPlatform(bool isGetStart) const;