Rebaseline paint/invalidation/repaint-overlay/layers-overlay.html

TBR=wangxianzhu@chromium.org

Change-Id: I15be67b385349af7da4c47d3763ba08c5141061d
Reviewed-on: https://chromium-review.googlesource.com/c/1297986Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602513}

third_party/WebKit/LayoutTests/paint/invalidation/repaint-overlay/layers-overlay.html

@@ -82,7 +82,7 @@ var expected = {
         {
           "object": "LayoutBlockFlow (relative positioned) DIV id='child1'",
           "rect": [20, 20, 10, 10],
-          "reason": "style change"
+          "reason": "background"
         }
       ],
       "transform": 1
@@ -116,7 +116,7 @@ var expected = {
         {
           "object": "LayoutBlockFlow (relative positioned) DIV id='child2'",
           "rect": [20, 20, 10, 10],
-          "reason": "style change"
+          "reason": "background"
         }
       ],
       "transform": 4
@@ -216,7 +216,7 @@ var actual = {
         {
           "object": "LayoutBlockFlow (relative positioned) DIV id='child1'",
           "rect": [20, 20, 10, 10],
-          "reason": "style change"
+          "reason": "background"
         }
       ],
       "transform": 1
@@ -250,7 +250,7 @@ var actual = {
         {
           "object": "LayoutBlockFlow (relative positioned) DIV id='child2'",
           "rect": [20, 20, 10, 10],
-          "reason": "style change"
+          "reason": "background"
         }
       ],
       "transform": 4