Block modal dialogs inside sandboxes.

LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html

Index: LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html
diff --git a/LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html b/LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html
index 354beceab71cf82ed9829de1854ca1e9257a2355..19ca81d189d5b8c1f445e1b319a2b4b5db24afd0 100644
--- a/LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html
+++ b/LayoutTests/http/tests/security/xss-DENIED-window-name-navigator.html
@@ -6,22 +6,22 @@ if (window.testRunner)
         src="data:text/html,<script>
             try {
               top.navigator;
-              alert('FAIL');
+              console.log('FAIL');
             } catch(e) {
-              alert(e);
+              console.log(e);
             }
             this.x = 7;
             window.name='navigator';
-            alert(top.navigator === this ? 'PASS' : 'FAIL');
-            alert(top.navigator.x === 7 ? 'PASS' : 'FAIL');
+            console.log(top.navigator === this ? 'PASS' : 'FAIL');
+            console.log(top.navigator.x === 7 ? 'PASS' : 'FAIL');
             </script>"></iframe>
 <iframe sandbox="allow-scripts"
         src="data:text/html,<script>
-            alert(top.navigator !== this ? 'PASS' : 'FAIL');
+            console.log(top.navigator !== this ? 'PASS' : 'FAIL');
             try {
               top.navigator.x;
-              alert('FAIL');
+              console.log('FAIL');
             } catch(e) {
-              alert(e);
+              console.log(e);
             }
             </script>"></iframe>