Migrate <cr-dialog> from PaperDialogBehavior to native <dialog>.

chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js

Index: chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
diff --git a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
index b79d1ce38f050f2a1402adb1802ce0e84ec31b83..efe2b054179524563fdfd0fa37984ee861925025 100644
--- a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
+++ b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.js
@@ -85,7 +85,7 @@ Polymer({
         settings.ClearBrowsingDataBrowserProxyImpl.getInstance();
     this.browserProxy_.initialize().then(function(isRemoving) {
       this.clearingInProgress_ = isRemoving;
-      this.$.dialog.open();
+      this.$.dialog.showModal();
     }.bind(this));
   },
 
@@ -113,7 +113,6 @@ Polymer({
   updateFooter_: function(syncing, otherFormsOfBrowsingHistory) {
     this.$.googleFooter.hidden = !otherFormsOfBrowsingHistory;
     this.$.syncedDataSentence.hidden = !syncing;
-    this.$.dialog.notifyResize();
     this.$.dialog.classList.add('fully-rendered');
   },
 
@@ -132,7 +131,7 @@ Polymer({
   },
 
   open: function() {
-    this.$.dialog.open();
+    this.$.dialog.showModal();
   },
 
   /**
@@ -153,6 +152,11 @@ Polymer({
       }.bind(this));
   },
 
+  /** @private */
+  onCancelTap_: function() {
+    this.$.dialog.cancel();
+  },
+
   /**
    * Handles the closing of the notice about other forms of browsing history.
    * @private