Fix DNS.SB DoH entry

The server template never got updated on a previous format change, but
still managed to compile.  Add a validation in the constructor to ensure
only valid server templates are listed.  Also add a test to make sure
the list can be loaded without error (not completely necessary since
other tests load the list, but a specific test helps make it extra
obvious).

Bug: 1065338
Change-Id: Ie2b131a37bf7bd82c46747b5ab4e67d5b2f7eb7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2153319
Commit-Queue: Eric Orth <ericorth@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Auto-Submit: Eric Orth <ericorth@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759803}

net/dns/public/BUILD.gn

@@ -34,7 +34,10 @@ source_set("public") {
 
 source_set("tests") {
   testonly = true
-  sources = [ "util_unittest.cc" ]
+  sources = [
+    "doh_provider_list_unittest.cc",
+    "util_unittest.cc",
+  ]
 
   deps = [
     "//net",

net/dns/public/doh_provider_list.cc

@@ -8,6 +8,7 @@
 
 #include "base/logging.h"
 #include "base/no_destructor.h"
+#include "net/dns/public/util.h"
 
 namespace net {
 
@@ -29,6 +30,10 @@ DohProviderEntry::DohProviderEntry(
       privacy_policy(std::move(privacy_policy)),
       display_globally(display_globally),
       display_countries(std::move(display_countries)) {
+  DCHECK(!this->dns_over_https_template.empty());
+  DCHECK(dns_util::IsValidDohTemplate(this->dns_over_https_template,
+                                      nullptr /* server_method */));
+
   DCHECK(!display_globally || this->display_countries.empty());
   if (display_globally || !this->display_countries.empty()) {
     DCHECK(!this->ui_name.empty());
@@ -103,10 +108,9 @@ const std::vector<DohProviderEntry>& GetDohProviderList() {
           "Dnssb", base::nullopt /* provider_id_for_histogram */,
           {"185.222.222.222", "185.184.222.222", "2a09::", "2a09::1"},
           {"dns.sb"} /* dns_over_tls_hostnames */,
-          {"https://doh.dns.sb/dns-query?no_ecs=true{&dns}",
-           false /* use_post */},
-          "" /* ui_name */, "" /* privacy_policy */,
-          false /* display_globally */, {} /* display_countries */),
+          "https://doh.dns.sb/dns-query?no_ecs=true{&dns}", "" /* ui_name */,
+          "" /* privacy_policy */, false /* display_globally */,
+          {} /* display_countries */),
       DohProviderEntry("Google", DohProviderIdForHistogram::kGoogle,
                        {"8.8.8.8", "8.8.4.4", "2001:4860:4860::8888",
                         "2001:4860:4860::8844"},

net/dns/public/doh_provider_list_unittest.cc

+// Copyright 2020 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 "net/dns/public/doh_provider_list.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+namespace {
+
+TEST(DohProviderListTest, GetDohProviderList) {
+  const std::vector<DohProviderEntry>& list = GetDohProviderList();
+  EXPECT_FALSE(list.empty());
+}
+
+}  // namespace
+}  // namespace net

net/dns/public/util.cc

@@ -51,9 +51,10 @@ bool IsValidDohTemplate(base::StringPiece server_template,
     return false;
   }
   // If the template contains a dns variable, use GET, otherwise use POST.
-  DCHECK(server_method);
-  *server_method =
-      (vars_found.find("dns") == vars_found.end()) ? "POST" : "GET";
+  if (server_method) {
+    *server_method =
+        (vars_found.find("dns") == vars_found.end()) ? "POST" : "GET";
+  }
   return true;
 }