use new readPixels, as old version using Config8888 is deprecated

Source/platform/graphics/GraphicsContext.cpp

Index: Source/platform/graphics/GraphicsContext.cpp
diff --git a/Source/platform/graphics/GraphicsContext.cpp b/Source/platform/graphics/GraphicsContext.cpp
index 610dd132735864e15c93a1af39b884ffc144ab92..5f8fc1109c2669579e506d99d1ce31415100ce46 100644
--- a/Source/platform/graphics/GraphicsContext.cpp
+++ b/Source/platform/graphics/GraphicsContext.cpp
@@ -410,12 +410,12 @@ void GraphicsContext::setColorFilter(ColorFilter colorFilter)
     stateToSet->setColorFilter(WebCoreColorFilterToSkiaColorFilter(colorFilter));
 }
 
-bool GraphicsContext::readPixels(SkBitmap* bitmap, int x, int y, SkCanvas::Config8888 config8888)
+bool GraphicsContext::readPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, int x, int y)
 {
     if (paintingDisabled())
         return false;
 
-    return m_canvas->readPixels(bitmap, x, y, config8888);
+    return m_canvas->readPixels(info, pixels, rowBytes, x, y);
 }
 
 void GraphicsContext::setMatrix(const SkMatrix& matrix)