Delete reduntdant 19 header files in ui/gfx of chromium (blink side)

This blink side patch has to be preceded to delete below reduntdant
19 header files in ui/gfx of chromium.
(Please refer to https://codereview.chromium.org/392013005/)
These header files need to be deleted 
since they were already moved from ui/gfx to ui/gfx/geometry.

[Rendunt 19 header files to be deleted on chromium-side]
ui/gfx/box_f.h
ui/gfx/point.h
ui/gfx/point3_f.h
ui/gfx/quad_f.h
ui/gfx/insets.h
ui/gfx/point_f.h
ui/gfx/vector2d.h
ui/gfx/matrix3_f.h
ui/gfx/size.h
ui/gfx/size_f.h
ui/gfx/rect.h
ui/gfx/rect_f.h
ui/gfx/rect_conversions.h
ui/gfx/size_conversions.h
ui/gfx/point_conversions.h
ui/gfx/vector2d_conversions.h
ui/gfx/safe_interget_conversions.h
ui/gfx/vector3d_f.h
ui/gfx/vector2d_f.h

BUG=395370

Review URL: https://codereview.chromium.org/400403002

git-svn-id: svn://svn.chromium.org/blink/trunk@178520 bbb929c8-8fbe-4397-9dbb-9b2b20218538