Issue #1705 - Part 4: Add scrollbar-width CSS keyword to CSS parser.

This should be all parts needed to add a brand new enum keyword including
getting the computed style from it...

1 files changed, 9 insertions, 0 deletions

diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index d2d89a57da..acf287ea8a 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -4024,6 +4024,7 @@ nsStyleUserInterface::nsStyleUserInterface(StyleStructContext aContext)
   , mPointerEvents(NS_STYLE_POINTER_EVENTS_AUTO)
   , mCursor(NS_STYLE_CURSOR_AUTO)
   , mCaretColor(StyleComplexColor::Auto())
+  , mScrollbarWidth(StyleScrollbarWidth::Auto)
 {
   MOZ_COUNT_CTOR(nsStyleUserInterface);
 }
@@ -4036,6 +4037,7 @@ nsStyleUserInterface::nsStyleUserInterface(const nsStyleUserInterface& aSource)
   , mCursor(aSource.mCursor)
   , mCursorImages(aSource.mCursorImages)
   , mCaretColor(aSource.mCaretColor)
+  , mScrollbarWidth(aSource.mScrollbarWidth)
 {
   MOZ_COUNT_CTOR(nsStyleUserInterface);
 }
@@ -4087,6 +4089,13 @@ nsStyleUserInterface::CalcDifference(const nsStyleUserInterface& aNewData) const
   if (mCaretColor != aNewData.mCaretColor) {
     hint |= nsChangeHint_RepaintFrame;
   }
+  
+  if (mScrollbarWidth != aNewData.mScrollbarWidth) {
+    // For scrollbar-width change, we need some special handling similar
+    // to overflow properties. Specifically, we may need to reconstruct
+    // the scrollbar or force reflow of the viewport scrollbar.
+    hint |= nsChangeHint_ScrollbarChange;
+  }
 
   return hint;
 }