Bug 1692596 - Fix include-what-you-use errors in widget/windows/ScrollbarUtils.{h,cpp}. r=emilio

Also avoid including nsLayoutUtils.h from a header file.

Differential Revision: https://phabricator.services.mozilla.com/D105071

widget/windows/ScrollbarUtil.cpp

@@ -5,11 +5,24 @@
 
 #include "ScrollbarUtil.h"
 
+#include "mozilla/Maybe.h"
 #include "mozilla/RelativeLuminanceUtils.h"
 #include "mozilla/StaticPrefs_widget.h"
+#include "nsLayoutUtils.h"
 #include "nsNativeTheme.h"
 #include "nsNativeBasicTheme.h"
 
+using mozilla::ComputedStyle;
+using mozilla::EventStates;
+using mozilla::Maybe;
+using mozilla::Nothing;
+using mozilla::RelativeLuminanceUtils;
+using mozilla::Some;
+using mozilla::StyleAppearance;
+using mozilla::StyleScrollbarWidth;
+
+namespace StaticPrefs = mozilla::StaticPrefs;
+
 /*static*/
 bool ScrollbarUtil::IsScrollbarWidthThin(ComputedStyle* aStyle) {
   auto scrollbarWidth = aStyle->StyleUIReset()->mScrollbarWidth;

widget/windows/ScrollbarUtil.h

@@ -6,12 +6,12 @@
 #ifndef ScrollbarUtil_h
 #define ScrollbarUtil_h
 
-#include "nsLayoutUtils.h"
+#include "nsITheme.h"
 #include "nsNativeTheme.h"
 
 class ScrollbarUtil {
  public:
-  static bool IsScrollbarWidthThin(ComputedStyle* aStyle);
+  static bool IsScrollbarWidthThin(mozilla::ComputedStyle* aStyle);
   static bool IsScrollbarWidthThin(nsIFrame* aFrame);
 
   // Returns the style for custom scrollbar if the scrollbar part frame should
@@ -19,17 +19,17 @@ class ScrollbarUtil {
   //
   // Optionally the caller can pass a pointer to aDarkScrollbar for whether
   // custom scrollbar may be drawn due to dark background.
-  static ComputedStyle* GetCustomScrollbarStyle(nsIFrame* aFrame,
-                                                bool* aDarkScrollbar = nullptr);
+  static mozilla::ComputedStyle* GetCustomScrollbarStyle(
+      nsIFrame* aFrame, bool* aDarkScrollbar = nullptr);
 
   static nscolor GetScrollbarButtonColor(nscolor aTrackColor,
-                                         EventStates aStates);
+                                         mozilla::EventStates aStates);
   static nscolor GetScrollbarArrowColor(nscolor aButtonColor);
   static nscolor GetScrollbarTrackColor(nsIFrame* aFrame);
   static nscolor GetScrollbarThumbColor(nsIFrame* aFrame,
-                                        EventStates aEventStates);
-  static Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
-      nsIFrame* aFrame, StyleAppearance aAppearance);
+                                        mozilla::EventStates aEventStates);
+  static mozilla::Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
+      nsIFrame* aFrame, mozilla::StyleAppearance aAppearance);
 
  protected:
   ScrollbarUtil() = default;