Add web shell matcher for address field.

ios/testing/earl_grey/wait_util.mm

Index: ios/testing/earl_grey/wait_util.mm
diff --git a/mojo/public/cpp/system/message.cc b/ios/testing/earl_grey/wait_util.mm
similarity index 50%
copy from mojo/public/cpp/system/message.cc
copy to ios/testing/earl_grey/wait_util.mm
index 09d8d46e6dd15407bd123489ab8bdacdfef381c6..5e3645baecf4968637b8a9b6f04bd141d6a79fbb 100644
--- a/mojo/public/cpp/system/message.cc
+++ b/ios/testing/earl_grey/wait_util.mm
@@ -2,12 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "mojo/public/cpp/system/message.h"
+#include "ios/testing/earl_grey/wait_util.h"
 
-namespace mojo {
-
-ScopedMessageHandle::~ScopedMessageHandle() {
+namespace testing {
 
+const NSTimeInterval kSpinDelaySeconds = 0.01;
+const NSTimeInterval kWaitForUIElementTimeout = 4.0;
 }
-
-}  // namespace mojo