--- a/mobile/android/base/java/org/mozilla/gecko/preferences/FontSizePreference.java
+++ b/mobile/android/base/java/org/mozilla/gecko/preferences/FontSizePreference.java
@@ -6,16 +6,17 @@
 package org.mozilla.gecko.preferences;
 
 import org.mozilla.gecko.R;
 
 import android.app.AlertDialog;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Color;
+import android.os.Bundle;
 import android.preference.DialogPreference;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.TypedValue;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
@@ -25,41 +26,46 @@ import android.widget.TextView;
 import java.util.HashMap;
 
 class FontSizePreference extends DialogPreference {
     private static final String LOGTAG = "FontSizePreference";
     private static final int TWIP_TO_PT_RATIO = 20; // 20 twip = 1 point.
     private static final int PREVIEW_FONT_SIZE_UNIT = TypedValue.COMPLEX_UNIT_PT;
     private static final int DEFAULT_FONT_INDEX = 2;
 
+    public static final String PREFSBUNDLE_SIZE = "size";
+    public static final String PREFSBUNDLE_TWIPS = "twips";
+
     private final Context mContext;
     /** Container for mPreviewFontView to allow for scrollable padding at the top of the view. */
     private ScrollView mScrollingContainer;
     private TextView mPreviewFontView;
     private Button mIncreaseFontButton;
     private Button mDecreaseFontButton;
 
-    private final String[] mFontTwipValues;
+    private final String[] mFontSizeValues;
+    private final int[] mFontTwipValues;
     private final String[] mFontSizeNames; // Ex: "Small".
     /** Index into the above arrays for the saved preference value (from Gecko). */
     private int mSavedFontIndex = DEFAULT_FONT_INDEX;
     /** Index into the above arrays for the currently displayed font size (the preview). */
     private int mPreviewFontIndex = mSavedFontIndex;
-    private final HashMap<String, Integer> mFontTwipToIndexMap;
+    private final HashMap<String, Integer> mFontSizeToIndexMap;
 
     public FontSizePreference(Context context, AttributeSet attrs) {
         super(context, attrs);
         mContext = context;
 
         final Resources res = mContext.getResources();
-        mFontTwipValues = res.getStringArray(R.array.pref_font_size_values);
+        mFontSizeValues = res.getStringArray(R.array.pref_font_size_values);
+        mFontTwipValues = res.getIntArray(R.array.pref_font_twip_values);
         mFontSizeNames = res.getStringArray(R.array.pref_font_size_entries);
-        mFontTwipToIndexMap = new HashMap<String, Integer>();
-        for (int i = 0; i < mFontTwipValues.length; ++i) {
-            mFontTwipToIndexMap.put(mFontTwipValues[i], i);
+        mFontSizeToIndexMap = new HashMap<>();
+        for (int i = 0; i < mFontSizeValues.length; ++i) {
+            mFontSizeToIndexMap.put(mFontSizeValues[i], i);
         }
     }
 
     @Override
     protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
         final LayoutInflater inflater =
             (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         View dialogView = inflater.inflate(R.layout.font_size_preference, null);
@@ -90,66 +96,68 @@ class FontSizePreference extends DialogP
                 if (mPreviewFontIndex == 0) {
                     mDecreaseFontButton.setEnabled(false);
                 }
             }
         });
         mIncreaseFontButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                mPreviewFontIndex = Math.min(mPreviewFontIndex + 1, mFontTwipValues.length - 1);
+                mPreviewFontIndex = Math.min(mPreviewFontIndex + 1, mFontSizeValues.length - 1);
                 updatePreviewFontSize(mFontTwipValues[mPreviewFontIndex]);
 
                 mDecreaseFontButton.setEnabled(true);
                 // If we reached the maximum index, disable the button.
-                if (mPreviewFontIndex == mFontTwipValues.length - 1) {
+                if (mPreviewFontIndex == mFontSizeValues.length - 1) {
                     mIncreaseFontButton.setEnabled(false);
                 }
             }
         });
     }
 
     @Override
     protected void onDialogClosed(boolean positiveResult) {
         super.onDialogClosed(positiveResult);
         if (!positiveResult) {
             mPreviewFontIndex = mSavedFontIndex;
             return;
         }
         mSavedFontIndex = mPreviewFontIndex;
-        final String twipVal = mFontTwipValues[mSavedFontIndex];
+        final Bundle prefsVal = new Bundle(2);
+        prefsVal.putString(PREFSBUNDLE_SIZE, mFontSizeValues[mSavedFontIndex]);
+        prefsVal.putInt(PREFSBUNDLE_TWIPS, mFontTwipValues[mSavedFontIndex]);
         final OnPreferenceChangeListener prefChangeListener = getOnPreferenceChangeListener();
         if (prefChangeListener == null) {
             Log.e(LOGTAG, "PreferenceChangeListener is null. FontSizePreference will not be saved to Gecko.");
             return;
         }
-        prefChangeListener.onPreferenceChange(this, twipVal);
+        prefChangeListener.onPreferenceChange(this, prefsVal);
     }
 
     /**
-     * Finds the index of the given twip value and sets it as the saved preference value. Also the
+     * Finds the index of the given size value and sets it as the saved preference value. Also the
      * current preview text size to the given value. Does not update the mPreviewFontView text size.
      */
-    protected void setSavedFontSize(String twip) {
-        final Integer index = mFontTwipToIndexMap.get(twip);
+    protected void setSavedFontSize(String size) {
+        final Integer index = mFontSizeToIndexMap.get(size);
         if (index != null) {
             mSavedFontIndex = index;
             mPreviewFontIndex = mSavedFontIndex;
             return;
         }
         resetSavedFontSizeToDefault();
-        Log.e(LOGTAG, "setSavedFontSize: Given font size does not exist in twip values map. Reverted to default font size.");
+        Log.e(LOGTAG, "setSavedFontSize: Given font size does not exist in size values map. Reverted to default font size.");
     }
 
     /**
      * Updates the mPreviewFontView to the given text size, resets the container's scroll to the top
      * left, and invalidates the view. Does not update the font indices.
      */
-    private void updatePreviewFontSize(String twip) {
-        float pt = convertTwipStrToPT(twip);
+    private void updatePreviewFontSize(int twip) {
+        float pt = (float) twip / TWIP_TO_PT_RATIO;
         // Android will not render a font size of 0 pt but for Gecko, 0 twip turns off font
         // inflation. Thus we special case 0 twip to display a renderable font size.
         if (pt == 0) {
             // Android adds an inexplicable extra margin on the smallest font size so to get around
             // this, we reinflate the view.
             ViewGroup parentView = (ViewGroup) mScrollingContainer.getParent();
             parentView.removeAllViews();
             final LayoutInflater inflater =
@@ -169,24 +177,20 @@ class FontSizePreference extends DialogP
     private void resetSavedFontSizeToDefault() {
         mSavedFontIndex = DEFAULT_FONT_INDEX;
         mPreviewFontIndex = mSavedFontIndex;
     }
 
     private void setButtonState(int index) {
         if (index == 0) {
             mDecreaseFontButton.setEnabled(false);
-        } else if (index == mFontTwipValues.length - 1) {
+        } else if (index == mFontSizeValues.length - 1) {
             mIncreaseFontButton.setEnabled(false);
         }
     }
 
     /**
      * Returns the name of the font size (ex: "Small") at the currently saved preference value.
      */
     protected String getSavedFontSizeName() {
         return mFontSizeNames[mSavedFontIndex];
     }
-
-    private float convertTwipStrToPT(String twip) {
-        return Float.parseFloat(twip) / TWIP_TO_PT_RATIO;
-    }
 }

--- a/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java
+++ b/mobile/android/base/java/org/mozilla/gecko/preferences/GeckoPreferences.java
@@ -165,16 +165,17 @@ public class GeckoPreferences
     public static final String PREFS_NOTIFICATIONS_WHATS_NEW = NON_PREF_PREFIX + "notifications.whats_new";
     public static final String PREFS_APP_UPDATE_LAST_BUILD_ID = "app.update.last_build_id";
     public static final String PREFS_READ_PARTNER_CUSTOMIZATIONS_PROVIDER = NON_PREF_PREFIX + "distribution.read_partner_customizations_provider";
     public static final String PREFS_READ_PARTNER_BOOKMARKS_PROVIDER = NON_PREF_PREFIX + "distribution.read_partner_bookmarks_provider";
     public static final String PREFS_CUSTOM_TABS = NON_PREF_PREFIX + "customtabs";
     public static final String PREFS_ACTIVITY_STREAM = NON_PREF_PREFIX + "activitystream";
     public static final String PREFS_CATEGORY_EXPERIMENTAL_FEATURES = NON_PREF_PREFIX + "category_experimental";
     public static final String PREFS_COMPACT_TABS = NON_PREF_PREFIX + "compact_tabs";
+    public static final String PREFS_FONT_SIZE = "browser.zoom.globalZoom";
 
     private static final String ACTION_STUMBLER_UPLOAD_PREF = "STUMBLER_PREF";
 
 
     // This isn't a Gecko pref, even if it looks like one.
     private static final String PREFS_BROWSER_LOCALE = "locale";
 
     public static final String PREFS_RESTORE_SESSION = NON_PREF_PREFIX + "restoreSession3";
@@ -1217,17 +1218,23 @@ public class GeckoPreferences
                 }
             }, 1000);
         } else if (HANDLERS.containsKey(prefName)) {
             PrefHandler handler = HANDLERS.get(prefName);
             handler.onChange(this, preference, newValue);
         }
 
         // Send Gecko-side pref changes to Gecko
-        if (isGeckoPref(prefName)) {
+        if (prefName.equals(PREFS_FONT_SIZE)) {
+            String size = ((Bundle) newValue).getString(FontSizePreference.PREFSBUNDLE_SIZE);
+            PrefsHelper.setPref(prefName, size, false /* flush */);
+
+            int twips = ((Bundle) newValue).getInt(FontSizePreference.PREFSBUNDLE_TWIPS);
+            PrefsHelper.setPref("font.size.inflation.minTwips", twips, true /* flush */);
+        } else if (isGeckoPref(prefName)) {
             PrefsHelper.setPref(prefName, newValue, true /* flush */);
         }
 
         if (preference instanceof ListPreference) {
             // We need to find the entry for the new value
             int newIndex = ((ListPreference) preference).findIndexOfValue((String) newValue);
             CharSequence newEntry = ((ListPreference) preference).getEntries()[newIndex];
             ((ListPreference) preference).setSummary(newEntry);

--- a/mobile/android/base/resources/values/arrays.xml
+++ b/mobile/android/base/resources/values/arrays.xml
@@ -26,22 +26,29 @@
     <string-array name="pref_font_size_entries">
         <item>@string/pref_font_size_tiny</item>
         <item>@string/pref_font_size_small</item>
         <item>@string/pref_font_size_medium</item>
         <item>@string/pref_font_size_large</item>
         <item>@string/pref_font_size_xlarge</item>
     </string-array>
     <string-array name="pref_font_size_values">
+        <item>50</item>
+        <item>75</item>
+        <item>100</item>
+        <item>125</item>
+        <item>150</item>
+    </string-array>
+    <integer-array name="pref_font_twip_values">
         <item>0</item>
         <item>80</item>
         <item>120</item>
         <item>160</item>
         <item>240</item>
-    </string-array>
+    </integer-array>
     <string-array name="pref_char_encoding_entries">
         <item>@string/pref_char_encoding_on</item>
         <item>@string/pref_char_encoding_off</item>
     </string-array>
     <string-array name="pref_char_encoding_values">
         <item>true</item>
         <item>false</item>
     </string-array>

--- a/mobile/android/base/resources/xml/preferences_accessibility.xml
+++ b/mobile/android/base/resources/xml/preferences_accessibility.xml
@@ -3,17 +3,17 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
                   android:title="@string/pref_category_accessibility"
                   android:enabled="false">
 
     <org.mozilla.gecko.preferences.FontSizePreference
-                    android:key="font.size.inflation.minTwips"
+                    android:key="browser.zoom.globalZoom"
                     android:title="@string/pref_text_size"
                     android:positiveButtonText="@string/pref_font_size_set"
                     android:negativeButtonText="@string/button_cancel"
                     android:persistent="false" />
 
     <SwitchPreference android:key="browser.ui.zoom.force-user-scalable"
                       android:title="@string/pref_zoom_force_enabled"
                       android:summary="@string/pref_zoom_force_enabled_summary" />

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/PrefsHelper.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/PrefsHelper.java
@@ -26,17 +26,17 @@ public final class PrefsHelper {
     // Map pref name to ArrayList for multiple observers or PrefHandler for single observer.
     private static final SimpleArrayMap<String, Object> OBSERVERS = new SimpleArrayMap<>();
     private static final HashSet<String> INT_TO_STRING_PREFS = new HashSet<>(8);
     private static final HashSet<String> INT_TO_BOOL_PREFS = new HashSet<>(2);
 
     static {
         INT_TO_STRING_PREFS.add("browser.chrome.titlebarMode");
         INT_TO_STRING_PREFS.add("network.cookie.cookieBehavior");
-        INT_TO_STRING_PREFS.add("font.size.inflation.minTwips");
+        INT_TO_STRING_PREFS.add("browser.zoom.globalZoom");
         INT_TO_STRING_PREFS.add("home.sync.updateMode");
         INT_TO_STRING_PREFS.add("browser.image_blocking");
         INT_TO_BOOL_PREFS.add("browser.display.use_document_fonts");
     }
 
     @WrapForJNI
     private static final int PREF_INVALID = -1;
     @WrapForJNI