Mac: Don't repaint scrollbars every frame

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 15 matching lines @@
 #include "config.h"
 #include "platform/scroll/ScrollbarThemeMock.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/scroll/ScrollbarThemeClient.h"
 
 namespace blink {
 
+static bool gShouldRepaintAllPartsOnInvalidation = true;
+
+void ScrollbarThemeMock::setShouldRepaintAllPartsOnInvalidation(bool shouldRepaint)
+{
+    gShouldRepaintAllPartsOnInvalidation = shouldRepaint;
+}
+
 static int cScrollbarThickness[] = { 15, 11 };
 
-IntRect ScrollbarThemeMock::trackRect(const ScrollbarThemeClient* scrollbar, bool)
-{
-    return scrollbar->frameRect();
-}
-
 int ScrollbarThemeMock::scrollbarThickness(ScrollbarControlSize controlSize)
 {
     return cScrollbarThickness[controlSize];
 }
 
 bool ScrollbarThemeMock::usesOverlayScrollbars() const
 {
     return RuntimeEnabledFeatures::overlayScrollbarsEnabled();
 }
 
+bool ScrollbarThemeMock::shouldRepaintAllPartsOnInvalidation() const
+{
+    return gShouldRepaintAllPartsOnInvalidation;
+}
+
+IntRect ScrollbarThemeMock::trackRect(const ScrollbarThemeClient* scrollbar, bool)
+{
+    return scrollbar->frameRect();
+}
+
+
 void ScrollbarThemeMock::paintTrackBackground(GraphicsContext* context, const ScrollbarThemeClient* scrollbar, const IntRect& trackRect)
 {
     if (DrawingRecorder::useCachedDrawingIfPossible(*context, *scrollbar, DisplayItem::ScrollbarTrackBackground))
         return;
 
     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)
 {
     if (!scrollbar->enabled())
         return;
 
     if (DrawingRecorder::useCachedDrawingIfPossible(*context, *scrollbar, DisplayItem::ScrollbarThumb))
         return;
 
     DrawingRecorder recorder(*context, *scrollbar, DisplayItem::ScrollbarThumb, thumbRect);
     context->fillRect(thumbRect, Color::darkGray);
 }
 
 }