MD Settings: add escape hatch

chrome/browser/resources/settings/settings.js

Index: chrome/browser/resources/settings/settings.js
diff --git a/chrome/browser/resources/settings/settings.js b/chrome/browser/resources/settings/settings.js
index 8de03239b7aa266e64b1afe5c2012c5f174666a6..d8dea5620fe58da734e6ad7635d2e48051ce5b4f 100644
--- a/chrome/browser/resources/settings/settings.js
+++ b/chrome/browser/resources/settings/settings.js
@@ -16,4 +16,18 @@ Polymer({
   ready: function() {
     this.$.ui.directionDelegate = new settings.DirectionDelegateImpl;
   },
+
+  properties: {
+    appealClosed_: {
+      type: Boolean,
+      value: function() {
+        return !!(sessionStorage.appealClosed_ || localStorage.appealClosed_);
+      },
+    },
+  },
+
+  /** @private */
+  onCloseAppealTap_: function(e) {
+    sessionStorage.appealClosed_ = this.appealClosed_ = true;
+  },
 });