Refactor language detection logic to allow non-static CLD data sources.

chrome/browser/translate/standalone_cld_data_harness.h

 // 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.
 
 #ifndef CHROME_BROWSER_TRANSLATE_STANDALONE_CLD_DATA_HARNESS_H_
 #define CHROME_BROWSER_TRANSLATE_STANDALONE_CLD_DATA_HARNESS_H_
 
+#include "base/macros.h"
 #include "chrome/browser/translate/cld_data_harness.h"
 
 namespace test {
 
+// Utility class that sets up a test harness suitable for injecting a standalone
+// CLD data file into the runtime. See CldDataHarness class for more details.
 class StandaloneCldDataHarness : public CldDataHarness {
  public:
-  StandaloneCldDataHarness();
-  virtual ~StandaloneCldDataHarness();
-  virtual void Init() override;
+  StandaloneCldDataHarness() {}
+  ~StandaloneCldDataHarness() override;
+  void Init() override;
 
  private:
   void GetStandaloneDataFileSource(base::FilePath*);
   void GetStandaloneDataFileDestination(base::FilePath*);
   void DeleteStandaloneDataFile();
   void CopyStandaloneDataFile();
 
   DISALLOW_COPY_AND_ASSIGN(StandaloneCldDataHarness);
 };
 
 }  // namespace test
 
 #endif  // CHROME_BROWSER_TRANSLATE_STANDALONE_CLD_DATA_HARNESS_H_