AppUninstallDialog: Do not assume app domain is non-empty

AppUninstallDialog::InitializeCheckbox gets the app URL domain, and
changes the first domain character to upper-case, assuming that the
domain is non-empty. This may not be case if the app URL is an IP
address.

BUG=1084451

Change-Id: I5c43ff22fa3474a1c0ff0bcf79afd53de9beb26e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521043Reviewed-by: Nancy Wang <nancylingwang@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824671}

chrome/browser/ui/views/apps/app_dialog/app_uninstall_dialog_view.cc

@@ -202,8 +202,8 @@ void AppUninstallDialogView::InitializeCheckbox(const GURL& app_start_url) {
     auto domain = net::registry_controlled_domains::GetDomainAndRegistry(
         app_start_url,
         net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
-    DCHECK(!domain.empty());
-    domain[0] = base::ToUpperASCII(domain[0]);
+    if (!domain.empty())
+      domain[0] = base::ToUpperASCII(domain[0]);
 
     replacements.push_back(base::ASCIIToUTF16(domain));
   }