[RootLayerScrolls] Update test expectation for hidden-with-visible-text

This test has the expected layer tree diff, but the extra text in
the output caused it to be missed by the bulk updater.

BUG=711468
R=skobes@chromium.org

Change-Id: I37a5d27d7cbe03f6dd3baf287363f72f2efada2f
Reviewed-on: https://chromium-review.googlesource.com/677063
Commit-Queue: Stefan Zager <szager@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503598}

third_party/WebKit/LayoutTests/flag-specific/root-layer-scrolls/compositing/contents-opaque/hidden-with-visible-text-expected.txt

+Caption
+{
+  "layers": [
+    {
+      "name": "LayoutView #document",
+      "bounds": [800, 600],
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "Scrolling Layer",
+      "bounds": [800, 600],
+      "drawsContent": false
+    },
+    {
+      "name": "Scrolling Contents Layer",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "LayoutBlockFlow (positioned) DIV id='caption'",
+      "bounds": [200, 100],
+      "backgroundColor": "#008000",
+      "transform": 1
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [8, 13, 0, 1]
+      ]
+    }
+  ]
+}