--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoLayerClient.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoLayerClient.java
@@ -5,35 +5,31 @@
 
 package org.mozilla.gecko.gfx;
 
 import org.mozilla.gecko.annotation.RobocopTarget;
 import org.mozilla.gecko.annotation.WrapForJNI;
 import org.mozilla.gecko.EventDispatcher;
 import org.mozilla.gecko.util.GeckoBundle;
 
-import android.content.Context;
 import android.graphics.Color;
 import android.graphics.Matrix;
 import android.graphics.PointF;
 import android.graphics.RectF;
 import android.os.SystemClock;
-import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.InputDevice;
 import android.view.MotionEvent;
 
 import java.util.ArrayList;
 
 class GeckoLayerClient implements LayerView.Listener
 {
     private static final String LOGTAG = "GeckoLayerClient";
 
-    private final Context mContext;
-    private IntSize mScreenSize;
     private IntSize mWindowSize;
 
     private boolean mForceRedraw;
     private boolean mImeWasEnabledOnLastResize;
 
     /* The current viewport metrics.
      * This is volatile so that we can read and write to it from different threads.
      * We avoid synchronization to make getting the viewport metrics from
@@ -60,26 +56,23 @@ class GeckoLayerClient implements LayerV
      * have the first-paint flag set, and the second paint happens concurrently with the
      * composite for the first paint, then this flag may be set to true prematurely. Fixing this
      * is possible but risky; see https://bugzilla.mozilla.org/show_bug.cgi?id=797615#c751
      */
     private volatile boolean mContentDocumentIsDisplayed;
 
     private SynthesizedEventState mPointerState;
 
-    public GeckoLayerClient(Context context, LayerView view) {
+    public GeckoLayerClient(LayerView view) {
         // we can fill these in with dummy values because they are always written
         // to before being read
-        mContext = context;
-        mScreenSize = new IntSize(0, 0);
         mWindowSize = new IntSize(0, 0);
 
         mForceRedraw = true;
-        DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
-        mViewportMetrics = new ImmutableViewportMetrics(displayMetrics)
+        mViewportMetrics = new ImmutableViewportMetrics()
                            .setViewportSize(view.getWidth(), view.getHeight());
 
         mToolbarAnimator = new DynamicToolbarAnimator(this);
         mPanZoomController = PanZoomController.Factory.create(view);
         mView = view;
         mView.setListener(this);
         mContentDocumentIsDisplayed = true;
     }
@@ -169,43 +162,33 @@ class GeckoLayerClient implements LayerV
     }
 
     DynamicToolbarAnimator getDynamicToolbarAnimator() {
         return mToolbarAnimator;
     }
 
     /* Informs Gecko that the screen size has changed. */
     private void sendResizeEventIfNecessary(boolean force) {
-        DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
-
-        IntSize newScreenSize = new IntSize(metrics.widthPixels, metrics.heightPixels);
         IntSize newWindowSize = new IntSize(mViewportMetrics.viewportRectWidth,
                                             mViewportMetrics.viewportRectHeight);
 
-        boolean screenSizeChanged = !mScreenSize.equals(newScreenSize);
         boolean windowSizeChanged = !mWindowSize.equals(newWindowSize);
 
-        if (!force && !screenSizeChanged && !windowSizeChanged) {
+        if (!force && !windowSizeChanged) {
             return;
         }
 
-        mScreenSize = newScreenSize;
         mWindowSize = newWindowSize;
 
-        if (screenSizeChanged) {
-            Log.d(LOGTAG, "Screen-size changed to " + mScreenSize);
-        }
-
         if (windowSizeChanged) {
             Log.d(LOGTAG, "Window-size changed to " + mWindowSize);
         }
 
         if (mView != null) {
-            mView.notifySizeChanged(mWindowSize.width, mWindowSize.height,
-                                    mScreenSize.width, mScreenSize.height);
+            mView.notifySizeChanged(mWindowSize.width, mWindowSize.height);
         }
     }
 
     @WrapForJNI(calledFrom = "gecko")
     void contentDocumentChanged() {
         mContentDocumentIsDisplayed = false;
     }
 

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/ImmutableViewportMetrics.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/ImmutableViewportMetrics.java
@@ -2,17 +2,16 @@
  * 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 android.graphics.PointF;
 import android.graphics.RectF;
-import android.util.DisplayMetrics;
 
 /**
  * ImmutableViewportMetrics are used to store the viewport metrics
  * in way that we can access a version of them from multiple threads
  * without having to take a lock
  */
 public class ImmutableViewportMetrics {
 
@@ -20,21 +19,21 @@ public class ImmutableViewportMetrics {
     // because Java doesn't have the concept of const classes
     public final float viewportRectLeft;
     public final float viewportRectTop;
     public final int viewportRectWidth;
     public final int viewportRectHeight;
 
     public final float zoomFactor;
 
-    public ImmutableViewportMetrics(DisplayMetrics metrics) {
-        viewportRectLeft   = 0;
-        viewportRectTop    = 0;
-        viewportRectWidth = metrics.widthPixels;
-        viewportRectHeight = metrics.heightPixels;
+    public ImmutableViewportMetrics() {
+        viewportRectLeft = 0;
+        viewportRectTop = 0;
+        viewportRectWidth = 0;
+        viewportRectHeight = 0;
         zoomFactor = 1.0f;
     }
 
     private ImmutableViewportMetrics(
         float aViewportRectLeft, float aViewportRectTop, int aViewportRectWidth,
         int aViewportRectHeight, float aZoomFactor)
     {
         viewportRectLeft = aViewportRectLeft;

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/LayerView.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/LayerView.java
@@ -118,18 +118,17 @@ public class LayerView extends FrameLayo
         @Override protected native void disposeNative();
 
         // Gecko thread sets its Java instances; does not block UI thread.
         @WrapForJNI(calledFrom = "any", dispatchTo = "gecko")
         /* package */ native void attachToJava(GeckoLayerClient layerClient,
                                                NativePanZoomController npzc);
 
         @WrapForJNI(calledFrom = "any", dispatchTo = "gecko")
-        /* package */ native void onSizeChanged(int windowWidth, int windowHeight,
-                                                int screenWidth, int screenHeight);
+        /* package */ native void onSizeChanged(int windowWidth, int windowHeight);
 
         // Gecko thread creates compositor; blocks UI thread.
         @WrapForJNI(calledFrom = "ui", dispatchTo = "proxy")
         /* package */ native void createCompositor(int width, int height, Object surface);
 
         // Gecko thread pauses compositor; blocks UI thread.
         @WrapForJNI(calledFrom = "ui", dispatchTo = "current")
         /* package */ native void syncPauseCompositor();
@@ -300,17 +299,17 @@ public class LayerView extends FrameLayo
         mDrawListeners = new ArrayList<DrawListener>();
     }
 
     public LayerView(Context context) {
         this(context, null);
     }
 
     public void initializeView() {
-        mLayerClient = new GeckoLayerClient(getContext(), this);
+        mLayerClient = new GeckoLayerClient(this);
         if (mOverscroll != null) {
             mLayerClient.setOverscrollHandler(mOverscroll);
         }
 
         mPanZoomController = mLayerClient.getPanZoomController();
         mToolbarAnimator = mLayerClient.getDynamicToolbarAnimator();
         mToolbarAnimator.notifyCompositorCreated(mCompositor);
 
@@ -627,18 +626,18 @@ public class LayerView extends FrameLayo
             mListener.surfaceChanged();
         }
 
         if (mOverscroll != null) {
             mOverscroll.setSize(width, height);
         }
     }
 
-    void notifySizeChanged(int windowWidth, int windowHeight, int screenWidth, int screenHeight) {
-        mCompositor.onSizeChanged(windowWidth, windowHeight, screenWidth, screenHeight);
+    void notifySizeChanged(int windowWidth, int windowHeight) {
+        mCompositor.onSizeChanged(windowWidth, windowHeight);
     }
 
     void serverSurfaceDestroyed() {
         ThreadUtils.assertOnUiThread();
 
         // We need to coordinate with Gecko when pausing composition, to ensure
         // that Gecko never executes a draw event while the compositor is paused.
         // This is sent synchronously to make sure that we don't attempt to use

--- a/widget/android/GeneratedJNIWrappers.h
+++ b/widget/android/GeneratedJNIWrappers.h
@@ -4063,22 +4063,20 @@ public:
     };
 
     struct OnSizeChanged_t {
         typedef Compositor Owner;
         typedef void ReturnType;
         typedef void SetterType;
         typedef mozilla::jni::Args<
                 int32_t,
-                int32_t,
-                int32_t,
                 int32_t> Args;
         static constexpr char name[] = "onSizeChanged";
         static constexpr char signature[] =
-                "(IIII)V";
+                "(II)V";
         static const bool isStatic = false;
         static const mozilla::jni::ExceptionMode exceptionMode =
                 mozilla::jni::ExceptionMode::ABORT;
         static const mozilla::jni::CallingThread callingThread =
                 mozilla::jni::CallingThread::ANY;
         static const mozilla::jni::DispatchTarget dispatchTarget =
                 mozilla::jni::DispatchTarget::GECKO;
     };

--- a/widget/android/nsWindow.cpp
+++ b/widget/android/nsWindow.cpp
@@ -916,18 +916,17 @@ public:
 
         // Set the first-paint flag so that we (re-)link any new Java objects
         // to Gecko, co-ordinate viewports, etc.
         if (RefPtr<CompositorBridgeChild> bridge = mWindow->GetCompositorBridgeChild()) {
             bridge->SendForceIsFirstPaint();
         }
     }
 
-    void OnSizeChanged(int32_t aWindowWidth, int32_t aWindowHeight,
-                       int32_t aScreenWidth, int32_t aScreenHeight)
+    void OnSizeChanged(int32_t aWindowWidth, int32_t aWindowHeight)
     {
         MOZ_ASSERT(NS_IsMainThread());
         if (!mWindow) {
             return; // Already shut down.
         }
 
         if (aWindowWidth != mWindow->mBounds.width ||
             aWindowHeight != mWindow->mBounds.height) {