Add missing (and remove superfluous) 'explicit' from constructors.

content/public/test/test_file_error_injector.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_TEST_TEST_FILE_ERROR_INJECTOR_H_
 #define CONTENT_PUBLIC_TEST_TEST_FILE_ERROR_INJECTOR_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 94 matching lines @@
   // Resets the found file list.
   void ClearFoundFiles();
 
   static std::string DebugString(FileOperationCode code);
 
  private:
   friend class base::RefCountedThreadSafe<TestFileErrorInjector>;
 
   typedef std::set<GURL> FileSet;
 
-  TestFileErrorInjector(
+  explicit TestFileErrorInjector(
       scoped_refptr<DownloadManager> download_manager);
 
   virtual ~TestFileErrorInjector();
 
   // Callbacks from the download file, to record lifetimes.
   // These may be called on any thread.
   void RecordDownloadFileConstruction(const GURL& url);
   void RecordDownloadFileDestruction(const GURL& url);
 
   // These run on the UI thread.
@@ skipping 15 matching lines @@
 
   // The download manager we set the factory on.
   scoped_refptr<DownloadManagerImpl> download_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(TestFileErrorInjector);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_TEST_FILE_ERROR_INJECTOR_H_