Revert "BScrollBar: Add lines and dots knob styles to scroll bar"

This reverts commit ec1b18c58a.

This was not well enough reviewed, and it seems that at least some
consumers of the old API (e.g. WebPositive) need more than the new one provides.

Change-Id: Ie7ad1fc70dab889922424298661504b00f66d31d

headers/os/interface/ControlLook.h

@@ -86,7 +86,6 @@ public:
 		B_FLAT					= 1 << 8, // flat look (e.g. button background)
 		B_INVALID				= 1 << 9, // invalid value, use B_FAILURE_COLOR
 		B_IS_CONTROL			= 1 << 10, // use control colors
-		B_SCROLLABLE			= 1 << 11, // scroll bar within bounds
 
 		B_BLEND_FRAME			= 1 << 16,
 	};
@@ -225,17 +224,15 @@ public:
 									const rgb_color& base,
 									uint32 flags = 0) = 0;
 
-	virtual	void				DrawScrollBar(BView* view, BRect& rect,
+	virtual	void				DrawScrollBarBackground(BView* view,
+									BRect& rect1, BRect& rect2,
 									const BRect& updateRect,
 									const rgb_color& base, uint32 flags,
-									orientation orientation,
-									bool doubleArrows = false,
-									int32 buttonDown = -1) = 0;
-	virtual	void				DrawScrollBarThumb(BView* view, BRect& rect,
-									BRect& thumbRect, const BRect& updateRect,
+									orientation orientation) = 0;
+	virtual	void				DrawScrollBarBackground(BView* view,
+									BRect& rect, const BRect& updateRect,
 									const rgb_color& base, uint32 flags,
-									orientation orientation,
-									uint32 knobStyle = 0) = 0;
+									orientation orientation) = 0;
 
 	virtual	void				DrawScrollViewFrame(BView* view,
 									BRect& rect, const BRect& updateRect,