Should not crash when background image a display:none presents on the root

LayoutTests/fast/backgrounds/root-background-display-none-no-crash-expected.txt

Index: LayoutTests/fast/backgrounds/root-background-display-none-no-crash-expected.txt
diff --git a/LayoutTests/fast/backgrounds/root-background-display-none-no-crash-expected.txt b/LayoutTests/fast/backgrounds/root-background-display-none-no-crash-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..b83ef219974536263554bcc75a9f613066b613ef
--- /dev/null
+++ b/LayoutTests/fast/backgrounds/root-background-display-none-no-crash-expected.txt
@@ -0,0 +1,15 @@
+
+html {

[pdr., 2015/06/24 02:31:40]

This doesn't seem quite right. Did you mean for this to be an -expected.html
file? Or, can you just document.write('PASS') instead of dumpAsText.

It looks like new technology is being built for these crash expectations, but
isn't quite ready yet.
https://groups.google.com/a/chromium.org/d/msg/blink-dev/MszepzweRq4/VtqGLPCK...
has more info.

[trchen, 2015/06/24 22:05:52]

Looks like dumpAsText is doing funny things when the root element has
display:none. document.write('PASS') solved the issue.

We still want dumpAsText() though, otherwise it wastes time dumping a white png.

+    display: none;
+    background-image: linear-gradient(black, black);
+}
+
+
+
+runAfterLayoutAndPaint(function(){
+    if (window.testRunner)
+        testRunner.dumpAsText();
+}, true);
+
+This test should not crash due to referencing a null root element renderer when painting root background.
+