CSS Transition: Fix flaky opacity-transition-zindex.html

third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt

Index: third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt
diff --git a/third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt b/third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt
index 98b699b41da9a49058824ee74ddd69609b89d86d..575a79e0bf025beb714dd769945fba1525454ff0 100644
--- a/third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt
+++ b/third_party/WebKit/LayoutTests/transitions/opacity-transition-zindex-expected.txt
@@ -2,11 +2,11 @@ layer at (0,0) size 800x600
   LayoutView at (0,0) size 800x600
 layer at (0,0) size 800x320
   LayoutBlockFlow {HTML} at (0,0) size 800x320
-    LayoutBlockFlow {BODY} at (8,10) size 784x300
-layer at (18,10) size 300x300 transparent layerType: background only
-layer at (168,160) size 100x100
+    LayoutBlockFlow {BODY} at (0,10) size 800x300

[suzyh_UTC10 (ex-contributor), 2016/12/21 00:37:45]

I'm surprised about this having an -expected.txt and an -expected.png. Wouldn't
the test only compare the output against one of them?

[Eric Willigers, 2016/12/21 01:22:36]

If we remove the txt,
  ...html failed unexpectedly (-expected.txt was missing)

If we remove the png,
  ...html failed unexpectedly (-expected.png was missing)

+layer at (10,10) size 300x300 transparent layerType: background only
+layer at (160,160) size 100x100
   LayoutBlockFlow (positioned) zI: -1 {DIV} at (150,150) size 100x100 [bgcolor=#FFA500]
-layer at (18,10) size 300x300 transparent layerType: foreground only
+layer at (10,10) size 300x300 transparent layerType: foreground only
   LayoutBlockFlow (relative positioned) {DIV} at (10,0) size 300x300 [bgcolor=#008000]
-layer at (28,20) size 200x200
+layer at (20,20) size 200x200
   LayoutBlockFlow (positioned) {DIV} at (10,10) size 200x200 [bgcolor=#0000FF]