Refactor DrawingRecorders to check for cached drawings earlier

Source/web/PageWidgetDelegate.cpp

Index: Source/web/PageWidgetDelegate.cpp
diff --git a/Source/web/PageWidgetDelegate.cpp b/Source/web/PageWidgetDelegate.cpp
index 74437cd62d55069b697132de06d21735aada426c..def3549942eda46213ad1ee85ab105f0adfb9ad0 100644
--- a/Source/web/PageWidgetDelegate.cpp
+++ b/Source/web/PageWidgetDelegate.cpp
@@ -95,9 +95,10 @@ void PageWidgetDelegate::paint(Page& page, PageOverlayList* overlays, WebCanvas*
             if (overlays)
                 overlays->paintWebFrame(paintContext);
         } else {
-            DrawingRecorder drawingRecorder(paintContext, root, DisplayItem::PageWidgetDelegateBackgroundFallback, dirtyRect);
-            if (!drawingRecorder.canUseCachedDrawing())
+            if (!DrawingRecorder::useCachedDrawingIfPossible(paintContext, root, DisplayItem::PageWidgetDelegateBackgroundFallback)) {

[Xianzhu, 2015/07/03 01:24:42]

Nit: can use 'else if' to avoid indentation change.

[pdr., 2015/07/03 02:38:05]

Done.

+                DrawingRecorder drawingRecorder(paintContext, root, DisplayItem::PageWidgetDelegateBackgroundFallback, dirtyRect);
                 paintContext.fillRect(dirtyRect, Color::white);
+            }
         }
     }
     pictureBuilder.endRecording()->playback(canvas);