--- a/mobile/android/base/java/org/mozilla/gecko/Tab.java
+++ b/mobile/android/base/java/org/mozilla/gecko/Tab.java
@@ -67,18 +67,16 @@ public class Tab {
     private final int mParentId;
     // Indicates the url was loaded from a source external to the app. This will be cleared
     // when the user explicitly loads a new url (e.g. clicking a link is not explicit).
     private final boolean mExternal;
     private boolean mBookmark;
     private int mFaviconLoadId;
     private String mContentType;
     private boolean mHasTouchListeners;
-    private ZoomConstraints mZoomConstraints;
-    private boolean mIsRTL;
     private final ArrayList<View> mPluginViews;
     private final HashMap<Object, Layer> mPluginLayers;
     private int mBackgroundColor;
     private int mState;
     private Bitmap mThumbnailBitmap;
     private boolean mDesktopMode;
     private boolean mEnteringReaderMode;
     private final Context mAppContext;
@@ -132,17 +130,16 @@ public class Tab {
         mBaseDomain = "";
         mUserRequested = "";
         mExternal = external;
         mParentId = parentId;
         mTitle = title == null ? "" : title;
         mSiteIdentity = new SiteIdentity();
         mHistoryIndex = -1;
         mContentType = "";
-        mZoomConstraints = new ZoomConstraints(false);
         mPluginViews = new ArrayList<View>();
         mPluginLayers = new HashMap<Object, Layer>();
         mState = shouldShowProgress(url) ? STATE_LOADING : STATE_SUCCESS;
         mLoadProgress = LOAD_PROGRESS_INIT;
 
         // At startup, the background is set to a color specified by LayerView
         // when the LayerView is created. Shortly after, this background color
         // will be used before the tab's content is shown.
@@ -408,32 +405,16 @@ public class Tab {
         if (mState != Tab.STATE_LOADING)
             mEnteringReaderMode = false;
     }
 
     public int getState() {
         return mState;
     }
 
-    public void setZoomConstraints(ZoomConstraints constraints) {
-        mZoomConstraints = constraints;
-    }
-
-    public ZoomConstraints getZoomConstraints() {
-        return mZoomConstraints;
-    }
-
-    public void setIsRTL(boolean aIsRTL) {
-        mIsRTL = aIsRTL;
-    }
-
-    public boolean getIsRTL() {
-        return mIsRTL;
-    }
-
     public void setHasTouchListeners(boolean aValue) {
         mHasTouchListeners = aValue;
     }
 
     public boolean getHasTouchListeners() {
         return mHasTouchListeners;
     }
 
@@ -683,17 +664,16 @@ public class Tab {
         setContentType(message.getString("contentType"));
         updateUserRequested(message.getString("userRequested"));
         mBaseDomain = message.optString("baseDomain");
 
         setHasFeeds(false);
         setHasOpenSearch(false);
         mSiteIdentity.reset();
         setSiteLogins(null);
-        setZoomConstraints(new ZoomConstraints(true));
         setHasTouchListeners(false);
         setBackgroundColor(DEFAULT_BACKGROUND_COLOR);
         setErrorType(ErrorType.NONE);
         setLoadProgressIfLoading(LOAD_PROGRESS_LOCATION_CHANGE);
 
         Tabs.getInstance().notifyListeners(this, Tabs.TabEvents.LOCATION_CHANGE, oldUrl);
     }
 

deleted file mode 100644
--- a/mobile/android/base/java/org/mozilla/gecko/ZoomConstraints.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
- * This Source Code Form is subject to the terms of the Mozilla Public
- * 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/. */
-
-package org.mozilla.gecko;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
-public final class ZoomConstraints {
-    private final boolean mAllowZoom;
-    private final boolean mAllowDoubleTapZoom;
-    private final float mMinZoom;
-    private final float mMaxZoom;
-
-    public ZoomConstraints(boolean allowZoom) {
-        mAllowZoom = allowZoom;
-        mAllowDoubleTapZoom = allowZoom;
-        mMinZoom = 0.0f;
-        mMaxZoom = 0.0f;
-    }
-
-    ZoomConstraints(JSONObject message) throws JSONException {
-        mAllowZoom = message.getBoolean("allowZoom");
-        mAllowDoubleTapZoom = message.getBoolean("allowDoubleTapZoom");
-        mMinZoom = (float)message.getDouble("minZoom");
-        mMaxZoom = (float)message.getDouble("maxZoom");
-    }
-
-    public final boolean getAllowZoom() {
-        return mAllowZoom;
-    }
-
-    public final boolean getAllowDoubleTapZoom() {
-        return mAllowDoubleTapZoom;
-    }
-
-    public final float getMinZoom() {
-        return mMinZoom;
-    }
-
-    public final float getMaxZoom() {
-        return mMaxZoom;
-    }
-}

--- a/mobile/android/base/java/org/mozilla/gecko/gfx/GeckoLayerClient.java
+++ b/mobile/android/base/java/org/mozilla/gecko/gfx/GeckoLayerClient.java
@@ -7,17 +7,16 @@ package org.mozilla.gecko.gfx;
 
 import org.mozilla.gecko.annotation.RobocopTarget;
 import org.mozilla.gecko.annotation.WrapForJNI;
 import org.mozilla.gecko.GeckoAppShell;
 import org.mozilla.gecko.GeckoEvent;
 import org.mozilla.gecko.gfx.LayerView.DrawListener;
 import org.mozilla.gecko.Tab;
 import org.mozilla.gecko.Tabs;
-import org.mozilla.gecko.ZoomConstraints;
 import org.mozilla.gecko.EventDispatcher;
 import org.mozilla.gecko.util.FloatUtils;
 import org.mozilla.gecko.AppConstants;
 
 import android.content.Context;
 import android.graphics.PointF;
 import android.graphics.RectF;
 import android.os.SystemClock;
@@ -86,18 +85,16 @@ class GeckoLayerClient implements LayerV
      * 1) reading mViewportMetrics from any thread is fine without synchronization
      * 2) writing to mViewportMetrics requires synchronizing on the layer controller object
      * 3) whenever reading multiple fields from mViewportMetrics without synchronization (i.e. in
      *    case 1 above) you should always first grab a local copy of the reference, and then use
      *    that because mViewportMetrics might get reassigned in between reading the different
      *    fields. */
     private volatile ImmutableViewportMetrics mViewportMetrics;
 
-    private ZoomConstraints mZoomConstraints;
-
     private volatile boolean mGeckoIsReady;
 
     private final PanZoomController mPanZoomController;
     private final DynamicToolbarAnimator mToolbarAnimator;
     private final LayerView mView;
 
     /* This flag is true from the time that browser.js detects a first-paint is about to start,
      * to the time that we receive the first-paint composite notification from the compositor.
@@ -122,23 +119,16 @@ class GeckoLayerClient implements LayerV
         mCurrentViewTransform = new ViewTransform(0, 0, 1);
         mProgressiveUpdateData = new ProgressiveUpdateData();
         mProgressiveUpdateDisplayPort = new DisplayPortMetrics();
 
         mForceRedraw = true;
         DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
         mViewportMetrics = new ImmutableViewportMetrics(displayMetrics)
                            .setViewportSize(view.getWidth(), view.getHeight());
-        mZoomConstraints = new ZoomConstraints(false);
-
-        Tab tab = Tabs.getInstance().getSelectedTab();
-        if (tab != null) {
-            mZoomConstraints = tab.getZoomConstraints();
-            mViewportMetrics = mViewportMetrics.setIsRTL(tab.getIsRTL());
-        }
 
         mFrameMetrics = mViewportMetrics;
 
         mDrawListeners = new ArrayList<DrawListener>();
         mToolbarAnimator = new DynamicToolbarAnimator(this);
         mPanZoomController = PanZoomController.Factory.create(this, view, eventDispatcher);
         mView = view;
         mView.setListener(this);
@@ -549,27 +539,16 @@ class GeckoLayerClient implements LayerV
         // Abort drawing stale low-precision content if there's a more recent
         // display-port in the pipeline.
         if (lowPrecision && !aHasPendingNewThebesContent) {
           mProgressiveUpdateData.abort = true;
         }
         return mProgressiveUpdateData;
     }
 
-    void setZoomConstraints(ZoomConstraints constraints) {
-        mZoomConstraints = constraints;
-    }
-
-    void setIsRTL(boolean aIsRTL) {
-        synchronized (getLock()) {
-            ImmutableViewportMetrics newMetrics = getViewportMetrics().setIsRTL(aIsRTL);
-            setViewportMetrics(newMetrics, false);
-        }
-    }
-
     /** The compositor invokes this function just before compositing a frame where the document
       * is different from the document composited on the last frame. In these cases, the viewport
       * information we have in Java is no longer valid and needs to be replaced with the new
       * viewport information provided. setPageRect will never be invoked on the same frame that
       * this function is invoked on; and this function will always be called prior to syncViewportInfo.
       */
     @WrapForJNI(allowMultithread = true)
     public void setFirstPaintViewport(float offsetX, float offsetY, float zoom,
@@ -580,34 +559,32 @@ class GeckoLayerClient implements LayerV
             Tab tab = Tabs.getInstance().getSelectedTab();
 
             RectF cssPageRect = new RectF(cssPageLeft, cssPageTop, cssPageRight, cssPageBottom);
             RectF pageRect = RectUtils.scaleAndRound(cssPageRect, zoom);
 
             final ImmutableViewportMetrics newMetrics = currentMetrics
                 .setViewportOrigin(offsetX, offsetY)
                 .setZoomFactor(zoom)
-                .setPageRect(pageRect, cssPageRect)
-                .setIsRTL(tab != null ? tab.getIsRTL() : false);
+                .setPageRect(pageRect, cssPageRect);
             // Since we have switched to displaying a different document, we need to update any
             // viewport-related state we have lying around. This includes mGeckoViewport and
             // mViewportMetrics. Usually this information is updated via handleViewportMessage
             // while we remain on the same document.
             post(new Runnable() {
                 @Override
                 public void run() {
                     mGeckoViewport = newMetrics;
                 }
             });
 
             setViewportMetrics(newMetrics);
 
             if (tab != null) {
                 mView.setBackgroundColor(tab.getBackgroundColor());
-                setZoomConstraints(tab.getZoomConstraints());
             }
 
             // At this point, we have just switched to displaying a different document than we
             // we previously displaying. This means we need to abort any panning/zooming animations
             // that are in progress and send an updated display port request to browser.js as soon
             // as possible. The call to PanZoomController.abortAnimation accomplishes this by calling the
             // forceRedraw function, which sends the viewport to gecko. The display port request is
             // actually a full viewport update, which is fine because if browser.js has somehow moved to
@@ -997,22 +974,16 @@ class GeckoLayerClient implements LayerV
     /** Implementation of PanZoomTarget */
     @Override
     public ImmutableViewportMetrics getViewportMetrics() {
         return mViewportMetrics;
     }
 
     /** Implementation of PanZoomTarget */
     @Override
-    public ZoomConstraints getZoomConstraints() {
-        return mZoomConstraints;
-    }
-
-    /** Implementation of PanZoomTarget */
-    @Override
     public FullScreenState getFullScreenState() {
         return mView.getFullScreenState();
     }
 
     /** Implementation of PanZoomTarget */
     @Override
     public PointF getVisibleEndOfLayerView() {
         return mToolbarAnimator.getVisibleEndOfLayerView();

--- a/mobile/android/base/java/org/mozilla/gecko/gfx/LayerView.java
+++ b/mobile/android/base/java/org/mozilla/gecko/gfx/LayerView.java
@@ -13,17 +13,16 @@ import org.mozilla.gecko.annotation.Robo
 import org.mozilla.gecko.annotation.WrapForJNI;
 import org.mozilla.gecko.AppConstants;
 import org.mozilla.gecko.AppConstants.Versions;
 import org.mozilla.gecko.EventDispatcher;
 import org.mozilla.gecko.GeckoAccessibility;
 import org.mozilla.gecko.GeckoAppShell;
 import org.mozilla.gecko.GeckoEvent;
 import org.mozilla.gecko.GeckoThread;
-import org.mozilla.gecko.ZoomConstraints;
 
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Point;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.graphics.SurfaceTexture;

--- a/mobile/android/base/java/org/mozilla/gecko/gfx/PanZoomTarget.java
+++ b/mobile/android/base/java/org/mozilla/gecko/gfx/PanZoomTarget.java
@@ -1,23 +1,20 @@
 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * 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/. */
 
 package org.mozilla.gecko.gfx;
 
-import org.mozilla.gecko.ZoomConstraints;
-
 import android.graphics.PointF;
 import android.graphics.RectF;
 
 public interface PanZoomTarget {
     public ImmutableViewportMetrics getViewportMetrics();
-    public ZoomConstraints getZoomConstraints();
     public FullScreenState getFullScreenState();
     public PointF getVisibleEndOfLayerView();
 
     public void setAnimationTarget(ImmutableViewportMetrics viewport);
     public void setViewportMetrics(ImmutableViewportMetrics viewport);
     public void scrollBy(float dx, float dy);
     public void panZoomStopped();
     /** This triggers an (asynchronous) viewport update/redraw. */

--- a/mobile/android/base/moz.build
+++ b/mobile/android/base/moz.build
@@ -657,17 +657,16 @@ gbjar.sources += ['java/org/mozilla/geck
     'widget/RoundedCornerLayout.java',
     'widget/SiteLogins.java',
     'widget/SquaredImageView.java',
     'widget/SquaredRelativeLayout.java',
     'widget/SwipeDismissListViewTouchListener.java',
     'widget/TabThumbnailWrapper.java',
     'widget/ThumbnailView.java',
     'widget/TwoWayView.java',
-    'ZoomConstraints.java',
     'ZoomedView.java',
 ]]
 # The following sources are checked in to version control but
 # generated by a script (java/org/mozilla/gecko/widget/themed/generate_themed_views.py).
 # If you're editing this list, make sure to edit that script.
 gbjar.sources += ['java/org/mozilla/gecko/' + x for x in [
     'widget/themed/ThemedEditText.java',
     'widget/themed/ThemedFrameLayout.java',