Make the LayoutRect->FloatRect constructor explicit.

Source/core/paint/FramePainter.cpp

Index: Source/core/paint/FramePainter.cpp
diff --git a/Source/core/paint/FramePainter.cpp b/Source/core/paint/FramePainter.cpp
index 440c82167af2173537d632b7902ed5dacc720331..f7fed460d6b72a90af612c66ec62c9914cc143dd 100644
--- a/Source/core/paint/FramePainter.cpp
+++ b/Source/core/paint/FramePainter.cpp
@@ -166,7 +166,7 @@ void FramePainter::paintScrollCorner(GraphicsContext* context, const IntRect& co
     if (frameView().scrollCorner()) {
         bool needsBackground = frameView().frame().isMainFrame();
         if (needsBackground && !LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*context, *frameView().layoutView(), DisplayItem::ScrollbarCorner)) {
-            LayoutObjectDrawingRecorder drawingRecorder(*context, *frameView().layoutView(), DisplayItem::ScrollbarCorner, cornerRect);
+            LayoutObjectDrawingRecorder drawingRecorder(*context, *frameView().layoutView(), DisplayItem::ScrollbarCorner, FloatRect(cornerRect));
             context->fillRect(cornerRect, frameView().baseBackgroundColor());
 
         }