Layers that have a backdrop-filter should paints contents

third_party/WebKit/Source/core/paint/BoxDecorationData.cpp

Index: third_party/WebKit/Source/core/paint/BoxDecorationData.cpp
diff --git a/third_party/WebKit/Source/core/paint/BoxDecorationData.cpp b/third_party/WebKit/Source/core/paint/BoxDecorationData.cpp
index ef35fb1fffab783a39ddaa21d7c09b690541270b..e29f743415e9f791428848fcfcbf082d5486ade8 100644
--- a/third_party/WebKit/Source/core/paint/BoxDecorationData.cpp
+++ b/third_party/WebKit/Source/core/paint/BoxDecorationData.cpp
@@ -15,7 +15,7 @@ namespace blink {
 BoxDecorationData::BoxDecorationData(const LayoutBox& layoutBox)
 {
     backgroundColor = layoutBox.style()->visitedDependentColor(CSSPropertyBackgroundColor);
-    hasBackground = backgroundColor.alpha() || layoutBox.style()->hasBackgroundImage();
+    hasBackground = backgroundColor.alpha() || layoutBox.style()->hasBackgroundImage() || layoutBox.style()->hasBackdropFilter();

[pdr., 2016/02/03 04:20:28]

Is it possible to write a test for this? It looks like it's only used for bleed
avoidance so I wonder if the backdrop filter check is needed.

One technique for writing these tests is to set hasBackground to false and see
what tests fail, then copy and modify those to use backdrop filter.

[jaydasika, 2016/02/05 02:10:02]

You are right, I have verified that its used only for bleed avoidance and so we
can remove this backdrop filter check.

     ASSERT(hasBackground == layoutBox.style()->hasBackground());
     hasBorderDecoration = layoutBox.style()->hasBorderDecoration();
     hasAppearance = layoutBox.style()->hasAppearance();