--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoSurface.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoSurface.java
@@ -2,25 +2,25 @@
  * 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.SurfaceTexture;
 
+import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.view.Surface;
 import android.util.Log;
 
 import java.util.HashMap;
 
 import org.mozilla.gecko.annotation.WrapForJNI;
-import org.mozilla.gecko.AppConstants.Versions;
 
 public final class GeckoSurface extends Surface {
     private static final String LOGTAG = "GeckoSurface";
 
     private static HashMap<Integer, GeckoSurfaceTexture> sSurfaceTextures = new HashMap<Integer, GeckoSurfaceTexture>();
 
     private int mHandle;
     private boolean mIsSingleBuffer;
@@ -85,9 +85,9 @@ public final class GeckoSurface extends 
     public boolean getAvailable() {
         return mIsAvailable;
     }
 
     @WrapForJNI
     public void setAvailable(boolean available) {
         mIsAvailable = available;
     }
-}
\ No newline at end of file
+}

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoSurfaceTexture.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/GeckoSurfaceTexture.java
@@ -1,23 +1,23 @@
 /* -*- 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 android.graphics.SurfaceTexture;
+import android.os.Build;
 import android.util.Log;
 
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.HashMap;
 
 import org.mozilla.gecko.annotation.WrapForJNI;
-import org.mozilla.gecko.AppConstants.Versions;
 
 public final class GeckoSurfaceTexture extends SurfaceTexture {
     private static final String LOGTAG = "GeckoSurfaceTexture";
     private static volatile int sNextHandle = 1;
     private static HashMap<Integer, GeckoSurfaceTexture> sSurfaceTextures = new HashMap<Integer, GeckoSurfaceTexture>();
 
     private int mHandle;
     private boolean mIsSingleBuffer;
@@ -118,17 +118,17 @@ public final class GeckoSurfaceTexture e
     }
 
     public synchronized void setListener(GeckoSurfaceTexture.Callbacks listener) {
         mListener = listener;
     }
 
     @WrapForJNI
     public static boolean isSingleBufferSupported() {
-        return Versions.feature19Plus;
+        return Build.VERSION.SDK_INT >= 19;
     }
 
     @WrapForJNI
     public void incrementUse() {
         mUseCount.incrementAndGet();
     }
 
     @WrapForJNI
@@ -137,17 +137,17 @@ public final class GeckoSurfaceTexture e
 
         if (useCount == 0) {
             synchronized (sSurfaceTextures) {
                 sSurfaceTextures.remove(mHandle);
             }
 
             setListener(null);
 
-            if (Versions.feature16Plus) {
+            if (Build.VERSION.SDK_INT >= 16) {
                 try {
                     detachFromGLContext();
                 } catch (Exception e) {
                     // This can throw if the EGL context is not current
                     // but we can't do anything about that now.
                 }
             }
 
@@ -188,9 +188,9 @@ public final class GeckoSurfaceTexture e
             return sSurfaceTextures.get(handle);
         }
     }
 
     public interface Callbacks {
         void onUpdateTexImage();
         void onReleaseTexImage();
     }
-}
\ No newline at end of file
+}

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/GeckoHlsAudioRenderer.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/GeckoHlsAudioRenderer.java
@@ -2,37 +2,36 @@
  * 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.media;
 
 import android.media.MediaCodec;
 import android.media.MediaCodec.BufferInfo;
 import android.media.MediaCodec.CryptoInfo;
+import android.os.Build;
 import android.util.Log;
 
 import org.mozilla.gecko.AppConstants;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.RendererCapabilities;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import com.google.android.exoplayer2.mediacodec.MediaCodecInfo;
 import com.google.android.exoplayer2.mediacodec.MediaCodecSelector;
 import com.google.android.exoplayer2.mediacodec.MediaCodecUtil;
 import com.google.android.exoplayer2.util.MimeTypes;
 
 import java.nio.ByteBuffer;
 
-import org.mozilla.gecko.AppConstants.Versions;
-
 public class GeckoHlsAudioRenderer extends GeckoHlsRendererBase {
     public GeckoHlsAudioRenderer(GeckoHlsPlayer.ComponentEventDispatcher eventDispatcher) {
         super(C.TRACK_TYPE_AUDIO, eventDispatcher);
-        assertTrue(Versions.feature16Plus);
+        assertTrue(Build.VERSION.SDK_INT >= 16);
         LOGTAG = getClass().getSimpleName();
         DEBUG = AppConstants.NIGHTLY_BUILD || AppConstants.DEBUG_BUILD;;
     }
 
     @Override
     public final int supportsFormat(Format format) {
         /*
          * FORMAT_EXCEEDS_CAPABILITIES : The Renderer is capable of rendering
@@ -68,17 +67,17 @@ public class GeckoHlsAudioRenderer exten
             return RendererCapabilities.FORMAT_UNSUPPORTED_SUBTYPE;
         }
         /*
          *  Note : If the code can make it to this place, ExoPlayer assumes
          *         support for unknown sampleRate and channelCount when
          *         SDK version is less than 21, otherwise, further check is needed
          *         if there's no sampleRate/channelCount in format.
          */
-        boolean decoderCapable = Versions.preLollipop ||
+        boolean decoderCapable = (Build.VERSION.SDK_INT < 21) ||
                                  ((format.sampleRate == Format.NO_VALUE ||
                                   decoderInfo.isAudioSampleRateSupportedV21(format.sampleRate)) &&
                                  (format.channelCount == Format.NO_VALUE ||
                                   decoderInfo.isAudioChannelCountSupportedV21(format.channelCount)));
         int formatSupport = decoderCapable ?
             RendererCapabilities.FORMAT_HANDLED :
             RendererCapabilities.FORMAT_EXCEEDS_CAPABILITIES;
         return RendererCapabilities.ADAPTIVE_NOT_SEAMLESS | formatSupport;

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/GeckoHlsVideoRenderer.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/GeckoHlsVideoRenderer.java
@@ -2,34 +2,33 @@
  * 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.media;
 
 import android.media.MediaCodec;
 import android.media.MediaCodec.BufferInfo;
 import android.media.MediaCodec.CryptoInfo;
+import android.os.Build;
 import android.util.Log;
 
 import org.mozilla.gecko.AppConstants;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import com.google.android.exoplayer2.mediacodec.MediaCodecInfo;
 import com.google.android.exoplayer2.mediacodec.MediaCodecSelector;
 import com.google.android.exoplayer2.mediacodec.MediaCodecUtil;
 import com.google.android.exoplayer2.RendererCapabilities;
 import com.google.android.exoplayer2.util.MimeTypes;
 
 import java.nio.ByteBuffer;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
-import org.mozilla.gecko.AppConstants.Versions;
-
 public class GeckoHlsVideoRenderer extends GeckoHlsRendererBase {
     /*
      * By configuring these states, initialization data is provided for
      * ExoPlayer's HlsMediaSource to parse HLS bitstream and then provide samples
      * starting with an Access Unit Delimiter including SPS/PPS for TS,
      * and provide samples starting with an AUD without SPS/PPS for FMP4.
      */
     private enum RECONFIGURATION_STATE {
@@ -50,17 +49,17 @@ public class GeckoHlsVideoRenderer exten
 
     // Contain CSD-0(SPS)/CSD-1(PPS) information (in AnnexB format) for
     // prepending each keyframe. When video format changes, this information
     // changes accordingly.
     private byte[] mCSDInfo = null;
 
     public GeckoHlsVideoRenderer(GeckoHlsPlayer.ComponentEventDispatcher eventDispatcher) {
         super(C.TRACK_TYPE_VIDEO, eventDispatcher);
-        assertTrue(Versions.feature16Plus);
+        assertTrue(Build.VERSION.SDK_INT >= 16);
         LOGTAG = getClass().getSimpleName();
         DEBUG = AppConstants.NIGHTLY_BUILD || AppConstants.DEBUG_BUILD;;
     }
 
     @Override
     public final int supportsMixedMimeTypeAdaptation() {
         return ADAPTIVE_NOT_SEAMLESS;
     }
@@ -100,17 +99,17 @@ public class GeckoHlsVideoRenderer exten
             Log.e(LOGTAG, e.getMessage());
         }
         if (decoderInfo == null) {
             return RendererCapabilities.FORMAT_UNSUPPORTED_SUBTYPE;
         }
 
         boolean decoderCapable = decoderInfo.isCodecSupported(format.codecs);
         if (decoderCapable && format.width > 0 && format.height > 0) {
-            if (Versions.preLollipop) {
+            if (Build.VERSION.SDK_INT < 21) {
                 try {
                     decoderCapable = format.width * format.height <= MediaCodecUtil.maxH264DecodableFrameSize();
                 } catch (MediaCodecUtil.DecoderQueryException e) {
                     Log.e(LOGTAG, e.getMessage());
                 }
                 if (!decoderCapable) {
                     if (DEBUG) {
                         Log.d(LOGTAG, "Check [legacyFrameSize, " +

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/MediaDrmProxy.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/MediaDrmProxy.java
@@ -11,18 +11,18 @@ import java.util.UUID;
 import org.mozilla.gecko.mozglue.JNIObject;
 import org.mozilla.gecko.annotation.WrapForJNI;
 import org.mozilla.gecko.AppConstants;
 
 import android.media.MediaCodecInfo;
 import android.media.MediaCodecList;
 import android.media.MediaCrypto;
 import android.media.MediaDrm;
+import android.os.Build;
 import android.util.Log;
-import android.os.Build;
 
 public final class MediaDrmProxy {
     private static final String LOGTAG = "GeckoMediaDrmProxy";
     private static final boolean DEBUG = false;
     private static final UUID WIDEVINE_SCHEME_UUID =
             new UUID(0xedef8ba979d64aceL, 0xa3c827dcd51d21edL);
 
     private static final String WIDEVINE_KEY_SYSTEM = "com.widevine.alpha";
@@ -43,17 +43,17 @@ public final class MediaDrmProxy {
 
     // A flag to avoid using the native object that has been destroyed.
     private boolean mDestroyed;
     private GeckoMediaDrm mImpl;
     private String mDrmStubId;
 
     private static boolean isSystemSupported() {
         // Support versions >= Marshmallow
-        if (AppConstants.Versions.preMarshmallow) {
+        if (Build.VERSION.SDK_INT < 23) {
             if (DEBUG) Log.d(LOGTAG, "System Not supported !!, current SDK version is " + Build.VERSION.SDK_INT);
             return false;
         }
         return true;
     }
 
     @WrapForJNI
     public static boolean isSchemeSupported(String keySystem) {

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/RemoteMediaDrmBridgeStub.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/media/RemoteMediaDrmBridgeStub.java
@@ -3,16 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.media;
 import org.mozilla.gecko.AppConstants;
 
 import java.util.ArrayList;
 
 import android.media.MediaCrypto;
+import android.os.Build;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.util.Log;
 
 final class RemoteMediaDrmBridgeStub extends IMediaDrmBridge.Stub implements IBinder.DeathRecipient {
     private static final String LOGTAG = "GeckoRemoteMediaDrmBridgeStub";
     private static final boolean DEBUG = false;
     private volatile IMediaDrmBridgeCallbacks mCallbacks = null;
@@ -141,22 +142,22 @@ final class RemoteMediaDrmBridgeStub ext
 
     /* package-private */ void assertTrue(boolean condition) {
         if (DEBUG && !condition) {
             throw new AssertionError("Expected condition to be true");
         }
     }
 
     RemoteMediaDrmBridgeStub(String keySystem, String stubId) throws RemoteException {
-        if (AppConstants.Versions.preLollipop) {
+        if (Build.VERSION.SDK_INT < 21) {
             Log.e(LOGTAG, "Pre-Lollipop should never enter here!!");
             throw new RemoteException("Error, unsupported version!");
         }
         try {
-            if (AppConstants.Versions.preMarshmallow) {
+            if (Build.VERSION.SDK_INT < 23) {
                 mBridge = new GeckoMediaDrmBridgeV21(keySystem);
             } else {
                 mBridge = new GeckoMediaDrmBridgeV23(keySystem);
             }
             mStubId = stubId;
             mBridgeStubs.add(this);
         } catch (Exception e) {
             throw new RemoteException("RemoteMediaDrmBridgeStub cannot create bridge implementation.");

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ActivityUtils.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/ActivityUtils.java
@@ -37,17 +37,17 @@ public class ActivityUtils {
                 newVis |= View.SYSTEM_UI_FLAG_LOW_PROFILE;
             }
         } else {
             // no need to prevent status bar to appear when exiting full screen
             preventDisplayStatusbar(activity, false);
             newVis = View.SYSTEM_UI_FLAG_VISIBLE;
         }
 
-        if (AppConstants.Versions.feature23Plus) {
+        if (Build.VERSION.SDK_INT >= 23) {
             // We also have to set SYSTEM_UI_FLAG_LIGHT_STATUS_BAR with to current system ui status
             // to support both light and dark status bar.
             final int oldVis = window.getDecorView().getSystemUiVisibility();
             newVis |= (oldVis & View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
         }
 
         window.getDecorView().setSystemUiVisibility(newVis);
     }

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/GeckoBundle.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/GeckoBundle.java
@@ -8,16 +8,17 @@ package org.mozilla.gecko.util;
 import org.mozilla.gecko.annotation.RobocopTarget;
 import org.mozilla.gecko.annotation.WrapForJNI;
 import org.mozilla.gecko.AppConstants;
 
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.support.v4.util.SimpleArrayMap;
 
 import java.lang.reflect.Array;
 import java.util.Arrays;
 import java.util.Collection;
@@ -740,17 +741,17 @@ public final class GeckoBundle implement
                 jsonValue = ((GeckoBundle) value).toJSONObject();
             } else if (value instanceof GeckoBundle[]) {
                 final GeckoBundle[] array = (GeckoBundle[]) value;
                 final JSONArray jsonArray = new JSONArray();
                 for (int j = 0; j < array.length; j++) {
                     jsonArray.put(array[j] == null ? JSONObject.NULL : array[j].toJSONObject());
                 }
                 jsonValue = jsonArray;
-            } else if (AppConstants.Versions.feature19Plus) {
+            } else if (Build.VERSION.SDK_INT >= 19) {
                 final Object wrapped = JSONObject.wrap(value);
                 jsonValue = wrapped != null ? wrapped : value.toString();
             } else if (value == null) {
                 jsonValue = JSONObject.NULL;
             } else if (value.getClass().isArray()) {
                 final JSONArray jsonArray = new JSONArray();
                 for (int j = 0; j < Array.getLength(value); j++) {
                     jsonArray.put(Array.get(value, j));