Implement an API to allow passing an "ap" parameter to component updates.

components/update_client/utils.cc

 // Copyright 2014 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 "components/update_client/utils.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 221 matching lines @@
 bool IsValidBrand(const std::string& brand) {
   const size_t kMaxBrandSize = 4;
   if (brand.size() > kMaxBrandSize)
     return false;
 
   return std::find_if_not(brand.begin(), brand.end(), [](char ch) {
            return base::IsAsciiAlpha(ch);
          }) == brand.end();
 }
 
+bool IsValidAp(const std::string& ap) {
+  const size_t kMaxApSize = 256;
+  if (ap.size() > kMaxApSize)
+    return false;
+
+  return std::find_if_not(ap.begin(), ap.end(), [](char ch) {
+           if (base::IsAsciiAlpha(ch) || base::IsAsciiDigit(ch))
+             return true;
+
+           const char kSpecialChars[] = "+-_=";
+           for (auto c : kSpecialChars) {
+             if (c == ch)
+               return true;
+           }
+
+           return false;
+         }) == ap.end();
+}
+
 void RemoveUnsecureUrls(std::vector<GURL>* urls) {
   DCHECK(urls);
   urls->erase(std::remove_if(
                   urls->begin(), urls->end(),
                   [](const GURL& url) { return !url.SchemeIsCryptographic(); }),
               urls->end());
 }
 
 }  // namespace update_client