[subresource_filter] Replace KMP by std::search.

components/subresource_filter/core/common/fuzzy_pattern_matching.cc

 // Copyright 2016 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/subresource_filter/core/common/fuzzy_pattern_matching.h"
 
+#include <algorithm>
+
 namespace subresource_filter {
 
 namespace {
 
 bool StartsWithFuzzyImpl(base::StringPiece text, base::StringPiece subpattern) {
   DCHECK_LE(subpattern.size(), text.size());
 
   for (size_t i = 0; i != subpattern.size(); ++i) {
     const char text_char = text[i];
     const char pattern_char = subpattern[i];
@@ skipping 11 matching lines @@
   return subpattern.size() <= text.size() &&
          StartsWithFuzzyImpl(text, subpattern);
 }
 
 bool EndsWithFuzzy(base::StringPiece text, base::StringPiece subpattern) {
   return subpattern.size() <= text.size() &&
          StartsWithFuzzyImpl(text.substr(text.size() - subpattern.size()),
                              subpattern);
 }
 
+size_t FindFuzzy(base::StringPiece text,
+                 base::StringPiece subpattern,
+                 size_t from) {
+  if (from > text.size())
+    return base::StringPiece::npos;
+  if (subpattern.empty())
+    return from;
+
+  auto fuzzy_compare = [](char text_char, char subpattern_char) {
+    return text_char == subpattern_char ||
+           (subpattern_char == kSeparatorPlaceholder && IsSeparator(text_char));
+  };
+
+  base::StringPiece::const_iterator found =
+      std::search(text.begin() + from, text.end(), subpattern.begin(),
+                  subpattern.end(), fuzzy_compare);
+  return found == text.end() ? base::StringPiece::npos : found - text.begin();
+}
+
 }  // namespace subresource_filter