Remove FontSizePrefs destroy() method as its a singleton class.

chrome/browser/android/accessibility/font_size_prefs_android.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_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_
 
 #include <jni.h>
 #include "base/android/scoped_java_ref.h"
 #include "base/observer_list.h"
 
 class PrefChangeRegistrar;
 class PrefService;
 
 /*
  * Native implementation of FontSizePrefs. This class is used to get and set
  * FontScaleFactor and ForceEnableZoom.
  */
 class FontSizePrefsAndroid {
  public:
   class Observer {
    public:
     virtual void OnChangeFontSize(float font) = 0;
     virtual void OnChangeForceEnableZoom(bool enabled) = 0;
   };
 
   FontSizePrefsAndroid(JNIEnv* env, jobject obj);
   ~FontSizePrefsAndroid();
-  void Destroy(JNIEnv* env, jobject obj);
 
   void SetFontScaleFactor(JNIEnv* env, jobject obj, jfloat font);
   float GetFontScaleFactor(JNIEnv* env, jobject obj);
   void SetForceEnableZoom(JNIEnv* env, jobject obj, jboolean enabled);
   bool GetForceEnableZoom(JNIEnv* env, jobject obj);
 
   void AddObserver(JNIEnv* env, jobject obj, jlong obs);
   void RemoveObserver(JNIEnv* env, jobject obj, jlong obs);
 
   static bool Register(JNIEnv* env);
@@ skipping 26 matching lines @@
 
   // FontSizePrefs::Observer implementation.
   virtual void OnChangeFontSize(float font) OVERRIDE;
   virtual void OnChangeForceEnableZoom(bool enabled) OVERRIDE;
 
  private:
   base::android::ScopedJavaGlobalRef<jobject> java_ref_;
 };
 
 #endif  // CHROME_BROWSER_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_