Add baselines for new tests from WebKit Update 44286:44342....

webkit/data/layout_tests/platform/chromium-linux/LayoutTests/fast/backgrounds/body-generated-image-propagated-to-root-expected.txt

Index: webkit/data/layout_tests/platform/chromium-linux/LayoutTests/fast/backgrounds/body-generated-image-propagated-to-root-expected.txt
===================================================================
--- webkit/data/layout_tests/platform/chromium-linux/LayoutTests/fast/backgrounds/body-generated-image-propagated-to-root-expected.txt	(revision 0)
+++ webkit/data/layout_tests/platform/chromium-linux/LayoutTests/fast/backgrounds/body-generated-image-propagated-to-root-expected.txt	(revision 0)
@@ -0,0 +1,23 @@
+layer at (0,0) size 800x600
+  RenderView at (0,0) size 800x600
+layer at (0,0) size 800x600
+  RenderBlock {HTML} at (0,0) size 800x600
+    RenderBody {BODY} at (8,8) size 784x576
+      RenderBlock {P} at (0,0) size 784x40 [bgcolor=#FFFFFF]
+        RenderText {#text} at (0,0) size 51x19
+          text run at (0,0) width 51: "Test for "
+        RenderInline {I} at (0,0) size 770x39
+          RenderInline {A} at (0,0) size 311x19 [color=#0000EE]
+            RenderText {#text} at (51,0) size 311x19
+              text run at (51,0) width 311: "https://bugs.webkit.org/show_bug.cgi?id=18445"
+          RenderText {#text} at (362,0) size 770x39
+            text run at (362,0) width 4: " "
+            text run at (366,0) width 404: "Assertion failure in CSSGradientValue::image() when the body"
+            text run at (0,20) width 227: "element has a background gradient"
+        RenderText {#text} at (227,20) size 4x19
+          text run at (227,20) width 4: "."
+      RenderBlock {P} at (0,56) size 784x40 [bgcolor=#FFFFFF]
+        RenderText {#text} at (0,0) size 775x39
+          text run at (0,0) width 355: "The test passes if the root element\x{2019}s background is a linear "
+          text run at (355,0) width 420: "gradient from black at the top to white at the bottom, and no assertion"
+          text run at (0,20) width 84: "failure occurs."