Provide the equivalent of GURL::DomainIs for url::Origin.

url/url_util.cc

 // Copyright 2013 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 "url/url_util.h"
 
 #include <stddef.h>
 #include <string.h>
 #include <vector>
 
@@ skipping 470 matching lines @@
   return DoFindAndCompareScheme(str, str_len, compare, found_scheme);
 }
 
 bool FindAndCompareScheme(const base::char16* str,
                           int str_len,
                           const char* compare,
                           Component* found_scheme) {
   return DoFindAndCompareScheme(str, str_len, compare, found_scheme);
 }
 
+bool DomainIs(base::StringPiece canonicalized_host,
+              base::StringPiece lower_ascii_domain) {
+  if (canonicalized_host.empty() || lower_ascii_domain.empty())
+    return false;
+
+  // If the host name ends with a dot but the input domain doesn't, then we
+  // ignore the dot in the host name.
+  size_t host_len = canonicalized_host.length();
+  if (canonicalized_host.back() == '.' && lower_ascii_domain.back() != '.')
+    --host_len;
+
+  if (host_len < lower_ascii_domain.length())
+    return false;
+
+  // |host_first_pos| is the start of the compared part of the host name, not
+  // start of the whole host name.
+  const char* host_first_pos =
+      canonicalized_host.data() + host_len - lower_ascii_domain.length();
+
+  if (!base::LowerCaseEqualsASCII(
+          base::StringPiece(host_first_pos, lower_ascii_domain.length()),
+          lower_ascii_domain)) {
+    return false;
+  }
+
+  // Make sure there aren't extra characters in host before the compared part;
+  // if the host name is longer than the input domain name, then the character
+  // immediately before the compared part should be a dot. For example,
+  // www.google.com has domain "google.com", but www.iamnotgoogle.com does not.
+  if (lower_ascii_domain[0] != '.' && host_len > lower_ascii_domain.length() &&
+      *(host_first_pos - 1) != '.') {
+    return false;
+  }
+
+  return true;
+}
+
 bool Canonicalize(const char* spec,
                   int spec_len,
                   bool trim_path_end,
                   CharsetConverter* charset_converter,
                   CanonOutput* output,
                   Parsed* output_parsed) {
   return DoCanonicalize(spec, spec_len, trim_path_end, charset_converter,
                         output, output_parsed);
 }
 
@@ skipping 121 matching lines @@
   return DoCompareSchemeComponent(spec, component, compare_to);
 }
 
 bool CompareSchemeComponent(const base::char16* spec,
                             const Component& component,
                             const char* compare_to) {
   return DoCompareSchemeComponent(spec, component, compare_to);
 }
 
 }  // namespace url