Adds mailto: URL support to app launching.

ios/chrome/browser/web/mailto_handler_gmail_unittest.mm

Index: ios/chrome/browser/web/mailto_handler_gmail_unittest.mm
diff --git a/ios/chrome/browser/web/mailto_handler_gmail_unittest.mm b/ios/chrome/browser/web/mailto_handler_gmail_unittest.mm
new file mode 100644
index 0000000000000000000000000000000000000000..165e66b3e0d3c9dad2726e2ef969daf4fd8b33ec
--- /dev/null
+++ b/ios/chrome/browser/web/mailto_handler_gmail_unittest.mm
@@ -0,0 +1,20 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ios/chrome/browser/web/mailto_handler_gmail.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/gtest_mac.h"
+#include "url/gurl.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+TEST(MailtoHandlerGmailTest, TestConstructor) {
+  MailtoHandlerGmail* handler = [[MailtoHandlerGmail alloc] init];
+  EXPECT_NSEQ(@"Gmail", [handler appName]);
+  EXPECT_NSEQ(@"422689480", [handler appStoreID]);
+  EXPECT_NSEQ(@"googlegmail:/co?", [handler beginningScheme]);
+}