CSS backdrop-filter other than 'none' should force stacking context.

third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt

Index: third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt
diff --git a/third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt b/third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt
index 6c04687f8d915395f4d5ea64e427ed488d99dd97..5b867938b3aa3e0c8c793cd2e067d8d9fa018587 100644
--- a/third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt
+++ b/third_party/WebKit/LayoutTests/compositing/overflow/scroll-parent-absolute-with-backdrop-filter-expected.txt
@@ -9,77 +9,64 @@
       "drawsContent": true,
       "children": [
         {
-          "name": "Squashing Containment Layer",
+          "name": "LayoutBlockFlow DIV id='top'",
+          "position": [8, 8],
+          "bounds": [500, 500],
           "shouldFlattenTransform": false,
+          "drawsContent": true,
           "children": [
             {
-              "name": "LayoutBlockFlow DIV id='top'",
-              "position": [8, 8],
-              "bounds": [500, 500],
+              "name": "Scrolling Layer",
+              "bounds": [485, 485],
               "shouldFlattenTransform": false,
-              "drawsContent": true,
               "children": [
                 {
-                  "name": "Scrolling Layer",
-                  "bounds": [485, 485],
-                  "shouldFlattenTransform": false,
+                  "name": "Scrolling Contents Layer",
+                  "bounds": [485, 5000],
+                  "drawsContent": true,
                   "children": [
                     {
-                      "name": "Scrolling Contents Layer",
-                      "bounds": [485, 5000],
-                      "drawsContent": true
-                    }
-                  ]
-                },
-                {
-                  "name": "Overflow Controls Host Layer",
-                  "bounds": [500, 500],
-                  "children": [
-                    {
-                      "name": "Horizontal Scrollbar Layer",
-                      "position": [0, 485],
-                      "bounds": [485, 15]
-                    },
-                    {
-                      "name": "Vertical Scrollbar Layer",
-                      "position": [485, 0],
-                      "bounds": [15, 485]
+                      "name": "LayoutBlockFlow (relative positioned) DIV id='child'",
+                      "bounds": [300, 300],
+                      "contentsOpaque": true,
+                      "drawsContent": true,
+                      "backfaceVisibility": "hidden",
+                      "backgroundColor": "#FFFF00"
                     },
                     {
-                      "name": "Scroll Corner Layer",
-                      "position": [485, 485],
-                      "bounds": [15, 15],
-                      "drawsContent": true
+                      "name": "LayoutBlockFlow (relative positioned) DIV id='tall'",
+                      "bounds": [20, 5000],
+                      "contentsOpaque": true,
+                      "drawsContent": true,
+                      "backgroundColor": "#FA8072"
                     }
                   ]
                 }
               ]
             },
             {
-              "name": "Squashing Layer (first squashed layer: LayoutBlockFlow (positioned) DIV id='middle')",
-              "position": [8, 8],
-              "bounds": [400, 400],
-              "drawsContent": true
+              "name": "Overflow Controls Host Layer",
+              "bounds": [500, 500],
+              "children": [
+                {
+                  "name": "Horizontal Scrollbar Layer",
+                  "position": [0, 485],
+                  "bounds": [485, 15]
+                },
+                {
+                  "name": "Vertical Scrollbar Layer",
+                  "position": [485, 0],
+                  "bounds": [15, 485]
+                },
+                {
+                  "name": "Scroll Corner Layer",
+                  "position": [485, 485],
+                  "bounds": [15, 15],
+                  "drawsContent": true
+                }
+              ]
             }
           ]
-        },
-        {
-          "name": "LayoutBlockFlow (relative positioned) DIV id='child'",
-          "position": [8, 8],
-          "bounds": [300, 300],
-          "contentsOpaque": true,
-          "drawsContent": true,
-          "backfaceVisibility": "hidden",
-          "backgroundColor": "#FFFF00"
-        },
-        {
-          "name": "LayoutBlockFlow (relative positioned) DIV id='tall'",
-          "position": [8, 8],
-          "bounds": [20, 5000],
-          "contentsOpaque": true,
-          "drawsContent": true,
-          "backgroundColor": "#FA8072",
-          "hasScrollParent": true
         }
       ]
     }