Cleanup: Style fixes in extensions/browser

extensions/browser/file_highlighter.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_FILE_HIGHLIGHTER_H_
 #define EXTENSIONS_BROWSER_FILE_HIGHLIGHTER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 23 matching lines @@
 
   // Get the portion of the manifest which should not be highlighted and is
   // after the feature.
   std::string GetAfterFeature() const;
 
   // Populate a DictionaryValue with the highlighted portions (in UTF16) of the
   // source file.
   void SetHighlightedRegions(base::DictionaryValue* dict) const;
 
  protected:
-  FileHighlighter(const std::string& contents);
+  explicit FileHighlighter(const std::string& contents);
 
   // The contents of the file we are parsing.
   std::string contents_;
 
   // The start of the feature.
   size_t start_;
 
   // The end of the feature.
   size_t end_;
 
@@ skipping 48 matching lines @@
   // Called from the constructor; determine the bounds of the line in the source
   // file.
   void Parse(size_t line_number);
 
   DISALLOW_COPY_AND_ASSIGN(SourceHighlighter);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_FILE_HIGHLIGHTER_H_