--- a/mobile/android/base/gfx/LayerRenderer.java
+++ b/mobile/android/base/gfx/LayerRenderer.java
@@ -388,17 +388,17 @@ public class LayerRenderer implements Ta
     }
 
     public Frame createFrame(ImmutableViewportMetrics metrics) {
         return new Frame(metrics);
     }
 
     class FadeRunnable implements Runnable {
         private boolean mStarted;
-        private long mRunAt;
+        long mRunAt; // Would be private but we need both file access and high performance.
 
         void scheduleStartFade(long delay) {
             mRunAt = SystemClock.elapsedRealtime() + delay;
             if (!mStarted) {
                 mView.postDelayed(this, delay);
                 mStarted = true;
             }
         }
@@ -499,17 +499,19 @@ public class LayerRenderer implements Ta
             if (!mPageContext.fuzzyEquals(mLastPageContext) && !hideScrollbars) {
                 // The viewport or page changed, so show the scrollbars again
                 // as per UX decision. Don't do this if we're disabling scrolling due to
                 // full-screen mode though.
                 mVertScrollLayer.unfade();
                 mHorizScrollLayer.unfade();
                 mFadeRunnable.scheduleStartFade(ScrollbarLayer.FADE_DELAY);
             } else if (mFadeRunnable.timeToFade()) {
-                boolean stillFading = mVertScrollLayer.fade() | mHorizScrollLayer.fade();
+                final long currentMillis = SystemClock.elapsedRealtime();
+                final boolean stillFading = mVertScrollLayer.fade(mFadeRunnable.mRunAt, currentMillis) |
+                        mHorizScrollLayer.fade(mFadeRunnable.mRunAt, currentMillis);
                 if (stillFading) {
                     mFadeRunnable.scheduleNextFadeFrame();
                 }
             }
             mLastPageContext = mPageContext;
 
             /* Update layers. */
             if (rootLayer != null) {

--- a/mobile/android/base/gfx/ScrollbarLayer.java
+++ b/mobile/android/base/gfx/ScrollbarLayer.java
@@ -15,17 +15,17 @@ import android.util.Log;
 
 import java.nio.FloatBuffer;
 import java.nio.ByteBuffer;
 
 public class ScrollbarLayer extends Layer {
     private static final String LOGTAG = "GeckoScrollbarLayer";
 
     public static final long FADE_DELAY = 500; // milliseconds before fade-out starts
-    private static final float FADE_AMOUNT = 0.03f; // how much (as a percent) the scrollbar should fade per frame
+    private static final float FADE_MILLIS = 250; // how long the scrollbar should take to fade
 
     private final boolean mVertical;
     private float mOpacity;
     private final Rect mDirtyRect;
     private IntSize mSize;
 
     private int[] mTextureIDs;
 
@@ -136,26 +136,27 @@ public class ScrollbarLayer extends Laye
 
     private void deactivateProgram() {
         GLES20.glDisableVertexAttribArray(mTextureHandle);
         GLES20.glDisableVertexAttribArray(mPositionHandle);
         GLES20.glUseProgram(0);
     }
 
     /**
-     * Decrease the opacity of the scrollbar by one frame's worth.
+     * Set the opacity of the scrollbar depending on how much time has
+     * passed from the given start time, current time, and the constant duration.
      * Return true if the opacity was decreased, or false if the scrollbars
      * are already fully faded out.
      */
-    public boolean fade() {
+    public boolean fade(final long startMillis, final long currentMillis) {
         if (FloatUtils.fuzzyEquals(mOpacity, 0.0f)) {
             return false;
         }
         beginTransaction(); // called on compositor thread
-        mOpacity = Math.max(mOpacity - FADE_AMOUNT, 0.0f);
+        mOpacity = Math.max(1 - (currentMillis - startMillis) / FADE_MILLIS, 0.0f);
         endTransaction();
         return true;
     }
 
     /**
      * Restore the opacity of the scrollbar to fully opaque.
      * Return true if the opacity was changed, or false if the scrollbars
      * are already fully opaque.