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

chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java

Index: chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java b/chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java
index 6878cfe7225c41c8d24bc595660bc05f1ed48963..d9a63a0cb2695382dfec510f878b916d608460d5 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/accessibility/FontSizePrefs.java
@@ -170,11 +170,6 @@ public class FontSizePrefs implements OnSharedPreferenceChangeListener {
         return nativeGetForceEnableZoom(mFontSizePrefsAndroidPtr);
     }
 
-    public void destroy() {
-        mSharedPreferences.unregisterOnSharedPreferenceChangeListener(this);
-        nativeDestroy(mFontSizePrefsAndroidPtr);
-    }
-
     private native void nativeAddObserver(long nativeFontSizePrefsAndroid,
             long nativeObserverPtr);
 
@@ -183,8 +178,6 @@ public class FontSizePrefs implements OnSharedPreferenceChangeListener {
 
     private native long nativeInit();
 
-    private native void nativeDestroy(long nativeFontSizePrefsAndroid);
-
     private native void nativeSetFontScaleFactor(long nativeFontSizePrefsAndroid, float font);
 
     private native float nativeGetFontScaleFactor(long nativeFontSizePrefsAndroid);