Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

third_party/WebKit/Source/platform/scroll/ScrollbarThemeMock.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
 bool ScrollbarThemeMock::usesOverlayScrollbars() const
 {
     return RuntimeEnabledFeatures::overlayScrollbarsEnabled();
 }
 
 bool ScrollbarThemeMock::shouldRepaintAllPartsOnInvalidation() const
 {
     return gShouldRepaintAllPartsOnInvalidation;
 }
 
-IntRect ScrollbarThemeMock::trackRect(const ScrollbarThemeClient* scrollbar, bool)
+IntRect ScrollbarThemeMock::trackRect(const ScrollbarThemeClient& scrollbar, bool)
 {
-    return scrollbar->frameRect();
+    return scrollbar.frameRect();
 }
 
-
-void ScrollbarThemeMock::paintTrackBackground(GraphicsContext* context, const ScrollbarThemeClient* scrollbar, const IntRect& trackRect)
+void ScrollbarThemeMock::paintTrackBackground(GraphicsContext& context, const ScrollbarThemeClient& scrollbar, const IntRect& trackRect)
 {
-    if (DrawingRecorder::useCachedDrawingIfPossible(*context, *scrollbar, DisplayItem::ScrollbarTrackBackground))
+    if (DrawingRecorder::useCachedDrawingIfPossible(context, scrollbar, DisplayItem::ScrollbarTrackBackground))
         return;
 
-    DrawingRecorder recorder(*context, *scrollbar, DisplayItem::ScrollbarTrackBackground, trackRect);
-    context->fillRect(trackRect, scrollbar->enabled() ? Color::lightGray : Color(0xFFE0E0E0));
+    DrawingRecorder recorder(context, scrollbar, DisplayItem::ScrollbarTrackBackground, trackRect);
+    context.fillRect(trackRect, scrollbar.enabled() ? Color::lightGray : Color(0xFFE0E0E0));
 }
 
-void ScrollbarThemeMock::paintThumb(GraphicsContext* context, const ScrollbarThemeClient* scrollbar, const IntRect& thumbRect)
+void ScrollbarThemeMock::paintThumb(GraphicsContext& context, const ScrollbarThemeClient& scrollbar, const IntRect& thumbRect)
 {
-    if (!scrollbar->enabled())
+    if (!scrollbar.enabled())
         return;
 
-    if (DrawingRecorder::useCachedDrawingIfPossible(*context, *scrollbar, DisplayItem::ScrollbarThumb))
+    if (DrawingRecorder::useCachedDrawingIfPossible(context, scrollbar, DisplayItem::ScrollbarThumb))
         return;
 
-    DrawingRecorder recorder(*context, *scrollbar, DisplayItem::ScrollbarThumb, thumbRect);
-    context->fillRect(thumbRect, Color::darkGray);
+    DrawingRecorder recorder(context, scrollbar, DisplayItem::ScrollbarThumb, thumbRect);
+    context.fillRect(thumbRect, Color::darkGray);
 }
 
 }