Fix a bug on scrollbar's checking theme states

xfa/fwl/theme/cfwl_scrollbartp.cpp

Index: xfa/fwl/theme/cfwl_scrollbartp.cpp
diff --git a/xfa/fwl/theme/cfwl_scrollbartp.cpp b/xfa/fwl/theme/cfwl_scrollbartp.cpp
index 54dfbe5531cf09fa247d3d3ba4f8e8ec2031bf7a..79d0ce72f9202c8787fc648971addcc7f4a62f41 100644
--- a/xfa/fwl/theme/cfwl_scrollbartp.cpp
+++ b/xfa/fwl/theme/cfwl_scrollbartp.cpp
@@ -51,7 +51,9 @@ FX_BOOL CFWL_ScrollBarTP::DrawBackground(CFWL_ThemeBackground* pParams) {
     return FALSE;
   IFWL_Widget* pWidget = pParams->m_pWidget;
   FWLTHEME_STATE eState = FWLTHEME_STATE_Normal;
-  switch (pParams->m_dwStates & 0x03) {
+  switch (pParams->m_dwStates &

[Tom Sepez, 2016/05/20 20:14:10]

Switching on flags seems wrong, what if two or more are set?

prefer if (x & a) {} else if (x & b) {} else if (x & c) {}.

[Wei Li, 2016/05/20 20:54:31]

Done.

+          (CFWL_PartState_Hovered | CFWL_PartState_Pressed |
+           CFWL_PartState_Disabled)) {
     case CFWL_PartState_Hovered: {
       eState = FWLTHEME_STATE_Hover;
       break;