Port some things in browser/{download,history}, minor things in common....

chrome/browser/history/snippet.h

 // Copyright (c) 2006-2008 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.
 
 // This module computes snippets of queries based on hits in the documents
 // for display in history search results.
 
 #ifndef CHROME_BROWSER_HISTORY_SNIPPET_H__
 #define CHROME_BROWSER_HISTORY_SNIPPET_H__
 
+#include <string>
 #include <vector>
 
 class Snippet {
  public:
   // Each pair in MatchPositions is the [begin, end) positions of a match
   // within a string.
   typedef std::vector<std::pair<int, int> > MatchPositions;
 
   // Parses an offsets string as returned from a sqlite full text index. An
   // offsets string encodes information about why a row matched a text query.
@@ skipping 37 matching lines @@
  private:
   // The text of the snippet.
   std::wstring text_;
 
   // The matches within text_.
   MatchPositions matches_;
 };
 
 #endif  // CHROME_BROWSER_HISTORY_SNIPPET_H__