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 598 matching lines @@
 void EncodeURIComponent(const char* input, int length, CanonOutput* output) {
   for (int i = 0; i < length; ++i) {
     unsigned char c = static_cast<unsigned char>(input[i]);
     if (IsComponentChar(c))
       output->push_back(c);
     else
       AppendEscapedChar(c, output);
   }
 }
 
+bool DomainIs(base::StringPiece canonicalized_host,
+              base::StringPiece lower_ascii_domain) {
+  DCHECK(!canonicalized_host.empty());

[engedy, 2016/08/26 16:48:14]

I think it would be safer if this shared stuff did the checking, and returned
false if either argument is the empty string.

Then we could get rid of the checking in the two places that call into this. 

Don't forget to add the new unittests in URLUtils.

[pkalinnikov, 2016/08/29 09:53:00]

Done.

+  DCHECK(!lower_ascii_domain.empty());
+
+  // 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 CompareSchemeComponent(const char* spec,
                             const Component& component,
                             const char* compare_to) {
   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