--- a/mobile/android/base/Makefile.in
+++ b/mobile/android/base/Makefile.in
@@ -25,17 +25,16 @@ GARBAGE_DIRS += classes db jars res sync
 generated_resources := \
   AndroidManifest.xml \
   res/raw/browsersearch.json \
   res/raw/suggestedsites.json \
   res/values/strings.xml \
   $(NULL)
 
 generated_files := \
-  ../geckoview/generated/preprocessed/org/mozilla/geckoview/BuildConfig.java \
   AndroidManifest.xml \
   generated/preprocessed/org/mozilla/gecko/AdjustConstants.java \
   generated/preprocessed/org/mozilla/gecko/AppConstants.java \
   generated/preprocessed/org/mozilla/gecko/MmaConstants.java \
   $(NULL)
 
 gradle_dir := $(topobjdir)/gradle/build/mobile/android
 

--- a/mobile/android/base/moz.build
+++ b/mobile/android/base/moz.build
@@ -107,25 +107,21 @@ with Files('../app/src/*/res/menu/*activ
     BUG_COMPONENT = ('Firefox for Android', 'Awesomescreen')
 
 with Files('../app/src/*/res/menu/browsersearch_contextmenu.xml'):
     BUG_COMPONENT = ('Firefox for Android', 'Awesomescreen')
 
 DIRS += ['locales']
 
 GENERATED_FILES += [
-    '../geckoview/generated/preprocessed/org/mozilla/geckoview/BuildConfig.java',
     'AndroidManifest.xml',
     'generated/preprocessed/org/mozilla/gecko/AdjustConstants.java',
     'generated/preprocessed/org/mozilla/gecko/AppConstants.java',
     'generated/preprocessed/org/mozilla/gecko/MmaConstants.java',
 ]
-w = GENERATED_FILES['../geckoview/generated/preprocessed/org/mozilla/geckoview/BuildConfig.java']
-w.script = 'generate_build_config.py:generate_java'
-w.inputs += ['../geckoview/BuildConfig.java.in']
 x = GENERATED_FILES['generated/preprocessed/org/mozilla/gecko/AdjustConstants.java']
 x.script = 'generate_build_config.py:generate_java'
 x.inputs += ['AdjustConstants.java.in']
 y = GENERATED_FILES['generated/preprocessed/org/mozilla/gecko/AppConstants.java']
 y.script = 'generate_build_config.py:generate_java'
 y.inputs += ['AppConstants.java.in']
 y = GENERATED_FILES['generated/preprocessed/org/mozilla/gecko/MmaConstants.java']
 y.script = 'generate_build_config.py:generate_java'

deleted file mode 100644
--- a/mobile/android/geckoview/BuildConfig.java.in
+++ /dev/null
@@ -1,106 +0,0 @@
-//#filter substitution
-/* -*- 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.geckoview;
-
-import android.os.Build;
-
-/**
- * A collection of constants that pertain to the build state of the GeckoView
- * library, sourced from build-time definitions.  This is a partial Java-side
- * substitute for nsIXULAppInfo, amongst other things.
- *
- * See also SysInfo.java, which includes some of the values available from
- * nsSystemInfo inside Gecko.
- */
-public class BuildConfig {
-    public static final String GRE_MILESTONE = "@GRE_MILESTONE@";
-
-    public static final String MOZ_APP_ABI = "@MOZ_APP_ABI@";
-    public static final String MOZ_APP_BASENAME = "@MOZ_APP_BASENAME@";
-
-    // For the benefit of future archaeologists:
-    // GRE_BUILDID is exactly the same as MOZ_APP_BUILDID unless you're running
-    // on XULRunner, which is never the case on Android.
-    public static final String MOZ_APP_BUILDID = "@MOZ_BUILDID@";
-    public static final String MOZ_APP_ID = "@MOZ_APP_ID@";
-    public static final String MOZ_APP_NAME = "@MOZ_APP_NAME@";
-    public static final String MOZ_APP_VENDOR = "@MOZ_APP_VENDOR@";
-    public static final String MOZ_APP_VERSION = "@MOZ_APP_VERSION@";
-    public static final String MOZ_APP_DISPLAYNAME = "@MOZ_APP_DISPLAYNAME@";
-    public static final String MOZ_APP_UA_NAME = "@MOZ_APP_UA_NAME@";
-
-    // MOZILLA_VERSION is already quoted when it gets substituted in. If we
-    // add additional quotes we end up with ""x.y"", which is a syntax error.
-    public static final String MOZILLA_VERSION = @MOZILLA_VERSION@;
-    public static final String OMNIJAR_NAME = "@OMNIJAR_NAME@";
-
-    public static final String USER_AGENT_GECKOVIEW_MOBILE = "Mozilla/5.0 (Android " +
-        Build.VERSION.RELEASE + "; Mobile; rv:" +
-        MOZ_APP_VERSION + ") Gecko/" +
-        MOZ_APP_VERSION + " GeckoView/" +
-        MOZ_APP_VERSION;
-
-    public static final String USER_AGENT_GECKOVIEW_TABLET = "Mozilla/5.0 (Android " +
-        Build.VERSION.RELEASE + "; Tablet; rv:" +
-        MOZ_APP_VERSION + ") Gecko/" +
-        MOZ_APP_VERSION + " GeckoView/" +
-        MOZ_APP_VERSION;
-
-    /**
-     * Target CPU architecture: "armeabi-v7a", "arm64-v8a", "x86", "mips", ..
-     */
-    public static final String ANDROID_CPU_ARCH = "@ANDROID_CPU_ARCH@";
-
-    public static final String MOZ_UPDATE_CHANNEL = "@MOZ_UPDATE_CHANNEL@";
-
-    public static final int MIN_SDK_VERSION = @MOZ_ANDROID_MIN_SDK_VERSION@;
-
-    // Is the underlying compiled C/C++ code compiled with --enable-debug?
-    public static final boolean DEBUG_BUILD =
-//#ifdef MOZ_DEBUG
-    true;
-//#else
-    false;
-//#endif
-
-    // See this wiki page for more details about channel specific build defines:
-    // https://wiki.mozilla.org/Platform/Channel-specific_build_defines
-    // This makes no sense for GeckoView and should be removed as soon as possible.
-    public static final boolean RELEASE_OR_BETA =
-//#ifdef RELEASE_OR_BETA
-    true;
-//#else
-    false;
-//#endif
-
-    // This makes no sense for GeckoView and should be removed as soon as possible.
-    public static final boolean NIGHTLY_BUILD =
-//#ifdef NIGHTLY_BUILD
-    true;
-//#else
-    false;
-//#endif
-
-    // This makes no sense for GeckoView and should be removed as soon as possible.
-    public static final boolean MOZ_CRASHREPORTER =
-//#ifdef MOZ_CRASHREPORTER
-    true;
-//#else
-    false;
-//#endif
-
-    // Official corresponds, roughly, to whether this build is performed on
-    // Mozilla's continuous integration infrastructure. You should disable
-    // developer-only functionality when this flag is set.
-    // This makes no sense for GeckoView and should be removed as soon as possible.
-    public static final boolean MOZILLA_OFFICIAL =
-//#ifdef MOZILLA_OFFICIAL
-    true;
-//#else
-    false;
-//#endif
-}

--- a/mobile/android/geckoview/build.gradle
+++ b/mobile/android/geckoview/build.gradle
@@ -48,18 +48,16 @@ android {
         manifestPlaceholders = project.ext.manifestPlaceholders
 
         versionCode computeVersionCode()
         versionName "${mozconfig.substs.MOZ_APP_VERSION}-${mozconfig.substs.MOZ_UPDATE_CHANNEL}"
         consumerProguardFiles 'proguard-rules.txt'
 
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
 
-        // TODO: ensure these fields always agree with mobile/android/geckoview/BuildConfig.java.in,
-        // either by diffing the processed files or by generating the output from a single source.
         buildConfigField 'String', "GRE_MILESTONE", "\"${mozconfig.substs.GRE_MILESTONE}\""
         // This should really come from the included binaries, but that's not easy.
         buildConfigField 'String', "MOZ_APP_ABI", mozconfig.substs['COMPILE_ENVIRONMENT'] ? "\"${ mozconfig.substs.TARGET_XPCOM_ABI}\"" : '"arm-eabi-gcc3"';
         buildConfigField 'String', "MOZ_APP_BASENAME", "\"${mozconfig.substs.MOZ_APP_BASENAME}\"";
 
         // For the benefit of future archaeologists:
         // GRE_BUILDID is exactly the same as MOZ_APP_BUILDID unless you're running
         // on XULRunner, which is never the case on Android.