Removing GraphicsContext from ImageBuffer

Source/platform/scroll/ScrollbarThemeMacNonOverlayAPI.mm

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 96 matching lines @@
 
     if (!hasButtons(scrollbar))
         trackInfo.enableState = kThemeTrackNothingToScroll;
     trackInfo.trackInfo.scrollbar.pressState = scrollbarPartToHIPressedState(scrollbar->pressedPart());
 
     SkCanvas* canvas = context->canvas();
     CGAffineTransform currentCTM = gfx::SkMatrixToCGAffineTransform(canvas->getTotalMatrix());
 
     // The Aqua scrollbar is buggy when rotated and scaled.  We will just draw into a bitmap if we detect a scale or rotation.
     bool canDrawDirectly = currentCTM.a == 1.0f && currentCTM.b == 0.0f && currentCTM.c == 0.0f && (currentCTM.d == 1.0f || currentCTM.d == -1.0f);
-    GraphicsContext* drawingContext = context;
     OwnPtr<ImageBuffer> imageBuffer;
+    SkCanvas* drawingCanvas;
     if (!canDrawDirectly) {
         trackInfo.bounds = IntRect(IntPoint(), scrollbar->frameRect().size());
 
         IntRect bufferRect(scrollbar->frameRect());
         bufferRect.intersect(damageRect);
         bufferRect.move(-scrollbar->frameRect().x(), -scrollbar->frameRect().y());
 
         imageBuffer = ImageBuffer::create(bufferRect.size());
         if (!imageBuffer)
             return true;
 
-        drawingContext = imageBuffer->context();
+        drawingCanvas = imageBuffer->canvas();
+    } else {
+        drawingCanvas = canvas;
     }
 
     // Draw the track and its thumb.
     gfx::SkiaBitLocker bitLocker(
-        drawingContext->canvas(),
+        drawingCanvas,
         ThemeMac::inflateRectForAA(scrollbar->frameRect()),
-        drawingContext->deviceScaleFactor());
+        canDrawDirectly ? context->deviceScaleFactor() : 1.0f);
     CGContextRef cgContext = bitLocker.cgContext();
     HIThemeDrawTrack(&trackInfo, 0, cgContext, kHIThemeOrientationNormal);
 
     IntRect tickmarkTrackRect = trackRect(scrollbar, false);
     if (!canDrawDirectly) {
         tickmarkTrackRect.setX(0);
         tickmarkTrackRect.setY(0);
     }
     // The ends are rounded and the thumb doesn't go there.
     tickmarkTrackRect.inflateY(-tickmarkTrackRect.width());
     // Inset a bit.
     tickmarkTrackRect.setX(tickmarkTrackRect.x() + 2);
     tickmarkTrackRect.setWidth(tickmarkTrackRect.width() - 5);
-    paintGivenTickmarks(drawingContext, scrollbar, tickmarkTrackRect, tickmarks);
+    paintGivenTickmarks(drawingCanvas, scrollbar, tickmarkTrackRect, tickmarks);
 
     if (!canDrawDirectly) {
         ASSERT(imageBuffer);
         context->drawImageBuffer(imageBuffer.get(),
             FloatRect(scrollbar->frameRect().location(), imageBuffer->size()));
     }
 
     return true;
 }
 
@@ skipping 151 matching lines @@
         return IntRect(scrollbar->x() + startWidth, scrollbar->y(), scrollbar->width() - totalWidth, thickness);
     return IntRect(scrollbar->x(), scrollbar->y() + startWidth, thickness, scrollbar->height() - totalWidth);
 }
 
 int ScrollbarThemeMacNonOverlayAPI::minimumThumbLength(ScrollbarThemeClient* scrollbar)
 {
     return cThumbMinLength[scrollbar->controlSize()];
 }
 
 }