Reduce buggy usage of the registry controlled domain service.

content/renderer/webpublicsuffixlist_impl.cc

Index: content/renderer/webpublicsuffixlist_impl.cc
diff --git a/content/renderer/webpublicsuffixlist_impl.cc b/content/renderer/webpublicsuffixlist_impl.cc
index e1e00c22be28c7c42184e38d29999cb81d9f7308..97faedc8659e2702521689caaebe308a6a48a847 100644
--- a/content/renderer/webpublicsuffixlist_impl.cc
+++ b/content/renderer/webpublicsuffixlist_impl.cc
@@ -5,6 +5,8 @@
 #include "content/renderer/webpublicsuffixlist_impl.h"
 
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/base/url_util.h"
+#include "url/url_canon.h"
 
 namespace content {
 
@@ -13,10 +15,16 @@ WebPublicSuffixListImpl::~WebPublicSuffixListImpl() {
 
 size_t WebPublicSuffixListImpl::getPublicSuffixLength(
     const blink::WebString& host) {
-  size_t result = net::registry_controlled_domains::GetRegistryLength(
-      host.utf8(),
-      net::registry_controlled_domains::INCLUDE_UNKNOWN_REGISTRIES,
-      net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
+#ifndef NDEBUG
+  // Blink should only be calling us with canonical URLs.
+  url::CanonHostInfo host_info;
+  DCHECK_EQ(net::CanonicalizeHost(host.utf8(), &host_info), host.utf8());
+#endif
+  size_t result =
+      net::registry_controlled_domains::GetRegistryLengthForCanonicalHost(
+          host.utf8(),
+          net::registry_controlled_domains::INCLUDE_UNKNOWN_REGISTRIES,
+          net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
   return result ? result : host.length();
 }