Replace LayoutObject::skipInvalidationWhenLaidOutChildren() with paintedOutputOfObjectHasNoEffect

third_party/WebKit/Source/core/layout/LayoutBox.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBox.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBox.cpp b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
index 89b23b078658cced2b4731d5f485539a9a6f9bb3..ea6938cc60b0b05e921669fe41345f0194df724b 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBox.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
@@ -2034,6 +2034,25 @@ bool LayoutBox::needsForcedBreakBefore(EBreak previousBreakAfterValue) const
     return isForcedFragmentainerBreakValue(classABreakPointValue(previousBreakAfterValue));
 }
 
+bool LayoutBox::canSkipUnforcedPaintInvalidation() const
+{
+    if (getSelectionState() != SelectionNone)

[chrishtr, 2016/08/03 20:33:50]

What's the (brief) explanation for this?

[Xianzhu, 2016/08/03 21:30:35]

Done.

+        return false;
+
+    // In case scrollbars got repositioned (which will typically happen if the layout object got
+    // resized), we cannot skip invalidation.
+    if (hasNonCompositedScrollbars())
+        return false;
+
+    if (hasBoxDecorationBackground() || styleRef().hasVisualOverflowingEffect())

[chrishtr, 2016/08/03 20:33:50]

ditto

[Xianzhu, 2016/08/03 21:30:35]

Done.

+        return false;
+
+    if (hasClipRelatedProperty() || hasControlClip())

[chrishtr, 2016/08/03 20:33:50]

ditto

[Xianzhu, 2016/08/03 21:30:35]

Done.

+        return false;
+
+    return true;
+}
+
 LayoutRect LayoutBox::localOverflowRectForPaintInvalidation() const
 {
     if (style()->visibility() != VISIBLE)