Use DrawingRecorder::canUseCachedDrawing

Source/core/paint/ImagePainter.cpp

Index: Source/core/paint/ImagePainter.cpp
diff --git a/Source/core/paint/ImagePainter.cpp b/Source/core/paint/ImagePainter.cpp
index f4388257d6c5f8bb97f712a37fc636ecb5e4f560..33c8853ba0ba25f560802dbf8eeee306130f1042 100644
--- a/Source/core/paint/ImagePainter.cpp
+++ b/Source/core/paint/ImagePainter.cpp
@@ -64,7 +64,10 @@ void ImagePainter::paintAreaElementFocusRing(const PaintInfo& paintInfo)
     // https://crbug.com/251206
     GraphicsContextStateSaver savedContext(*paintInfo.context);
     IntRect focusRect = m_renderImage.absoluteContentBox();
-    RenderDrawingRecorder recorder(paintInfo.context, &m_renderImage, paintInfo.phase, focusRect);
+    RenderDrawingRecorder recorder(paintInfo.context, m_renderImage, paintInfo.phase, focusRect);
+    if (recorder.canUseCachedDrawing())
+        return;
+
     paintInfo.context->clip(focusRect);
     paintInfo.context->drawFocusRing(path, outlineWidth,
         areaElementStyle->outlineOffset(),
@@ -85,18 +88,27 @@ void ImagePainter::paintReplaced(const PaintInfo& paintInfo, const LayoutPoint&
         if (cWidth > 2 && cHeight > 2) {
             // Draw an outline rect where the image should be.
             IntRect paintRect = pixelSnappedIntRect(LayoutRect(paintOffset.x() + m_renderImage.borderLeft() + m_renderImage.paddingLeft(), paintOffset.y() + m_renderImage.borderTop() + m_renderImage.paddingTop(), cWidth, cHeight));
-            RenderDrawingRecorder recorder(context, &m_renderImage, paintInfo.phase, paintRect);
+            RenderDrawingRecorder recorder(context, m_renderImage, paintInfo.phase, paintRect);
+            if (recorder.canUseCachedDrawing())
+                return;
+
             context->setStrokeStyle(SolidStroke);
             context->setStrokeColor(Color::lightGray);
             context->setFillColor(Color::transparent);
             context->drawRect(paintRect);
         }
-    } else if (cWidth > 0 && cHeight > 0) {

[chrishtr, 2014/12/12 00:18:08]

Why the change to get rid of the else clause?

[Xianzhu, 2014/12/12 00:56:49]

Restored.

+        return;
+    }
+
+    if (cWidth > 0 && cHeight > 0) {
         LayoutRect contentRect = m_renderImage.contentBoxRect();
         contentRect.moveBy(paintOffset);
         LayoutRect paintRect = m_renderImage.replacedContentRect();
         paintRect.moveBy(paintOffset);
-        RenderDrawingRecorder recorder(context, &m_renderImage, paintInfo.phase, contentRect);
+        RenderDrawingRecorder recorder(context, m_renderImage, paintInfo.phase, contentRect);
+        if (recorder.canUseCachedDrawing())
+            return;
+
         bool clip = !contentRect.contains(paintRect);
         if (clip) {
             context->save();