Eagerly invalidate when a layer becomes stacking context

third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt

Index: third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt
diff --git a/third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt b/third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt
index c00db9dabfcdf9d0ec6086c0a5a418b438d1bf65..0a241bc2d7d6a744426e188e4c2762f8a194ff45 100644
--- a/third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt
+++ b/third_party/WebKit/LayoutTests/paint/invalidation/fixed-position-transparency-with-overflow-expected.txt
@@ -12,6 +12,16 @@
           "reason": "subtree"
         },
         {
+          "object": "LayoutBlockFlow (positioned) DIV class='absolute green'",
+          "rect": [108, 308, 100, 100],
+          "reason": "subtree"
+        },
+        {
+          "object": "LayoutBlockFlow (relative positioned) DIV id='container' class='relative blue'",
+          "rect": [8, 208, 100, 100],
+          "reason": "subtree"
+        },
+        {
           "object": "LayoutBlockFlow (relative positioned) DIV id='container' class='relative blue'",
           "rect": [8, 208, 100, 100],
           "reason": "subtree"
@@ -27,6 +37,14 @@
     {
       "object": "LayoutBlockFlow (positioned) DIV class='absolute green'",
       "reason": "subtree"
+    },
+    {
+      "object": "LayoutBlockFlow (relative positioned) DIV id='container' class='relative blue'",
+      "reason": "subtree"
+    },
+    {
+      "object": "LayoutBlockFlow (positioned) DIV class='absolute green'",
+      "reason": "subtree"
     }
   ]
 }