Scroller API: Changes

The following header file(s) have changed between 3.0 and 3.1

**Table 2:** aknscbut.h
Type	Class	Change
New public method	`CAknScrollButton`	`void SetContainerWindowL( const CCoeControl& aControl );`
New public method	`CAknScrollButton`	`TInt CountComponentControls() const;`
New public method	`CAknScrollButton`	`CCoeControl* ComponentControl( TInt aIndex ) const;`

**Table 3:** eiksbfrm.h
Type	Class	Change
New public method	`CEikScrollBarFrame`	`TInt DrawBackground(TBool aDrawHorizontal, TBool aDrawVertical);`
New public method	`CEikScrollBarFrame`	`TInt DrawBackgroundState(TBool& aDrawHorizontal, TBool& aDrawVertical);`

**Table 4:** eikscrlb.h
Type	Class	Change
New public method	`CAknDoubleSpanScrollBar`	`void SetScrollPopupInfoTextL( const TDesC& aText );`
New public method	`CAknDoubleSpanScrollBar`	`TBool DrawBackgroundState();`
New public method	`CAknDoubleSpanScrollBar`	`void DrawBackground(TBool aDrawHorizontal);`