Remove redundant field initialization in Java code.

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

 // 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.
 
 package org.chromium.chrome.browser.accessibility;
 
 import android.content.Context;
 import android.content.SharedPreferences;
 
 import org.chromium.base.ContextUtils;
@@ skipping 27 matching lines @@
     static final String PREF_USER_SET_FORCE_ENABLE_ZOOM = "user_set_force_enable_zoom";
     static final String PREF_USER_FONT_SCALE_FACTOR = "user_font_scale_factor";
 
     private static FontSizePrefs sFontSizePrefs;
 
     private final long mFontSizePrefsAndroidPtr;
     private final Context mApplicationContext;
     private final SharedPreferences mSharedPreferences;
     private final ObserverList<FontSizePrefsObserver> mObserverList;
 
-    private Float mSystemFontScaleForTests = null;
+    private Float mSystemFontScaleForTests;
 
     /**
      * Interface for observing changes in font size-related preferences.
      */
     public interface FontSizePrefsObserver {
         void onFontScaleFactorChanged(float fontScaleFactor, float userFontScaleFactor);
         void onForceEnableZoomChanged(boolean enabled);
     }
 
     private FontSizePrefs(Context context) {
@@ skipping 157 matching lines @@
         }
     }
 
     private native long nativeInit();
     private native void nativeSetFontScaleFactor(long nativeFontSizePrefsAndroid,
             float fontScaleFactor);
     private native float nativeGetFontScaleFactor(long nativeFontSizePrefsAndroid);
     private native boolean nativeGetForceEnableZoom(long nativeFontSizePrefsAndroid);
     private native void nativeSetForceEnableZoom(long nativeFontSizePrefsAndroid, boolean enabled);
 }