--- a/browser/confvars.sh
+++ b/browser/confvars.sh
@@ -33,17 +33,16 @@ if test "$NIGHTLY_BUILD"; then
   MOZ_RUST_URLPARSE=1
 fi
 
 # Enable building ./signmar and running libmar signature tests
 MOZ_ENABLE_SIGNMAR=1
 
 MOZ_APP_VERSION=$FIREFOX_VERSION
 MOZ_APP_VERSION_DISPLAY=$FIREFOX_VERSION_DISPLAY
-MOZ_EXTENSIONS_DEFAULT=" gio"
 # MOZ_APP_DISPLAYNAME will be set by branding/configure.sh
 # MOZ_BRANDING_DIRECTORY is the default branding directory used when none is
 # specified. It should never point to the "official" branding directory.
 # For mozilla-beta, mozilla-release, or mozilla-central repositories, use
 # "unofficial" branding.
 # For the mozilla-aurora repository, use "aurora".
 MOZ_BRANDING_DIRECTORY=browser/branding/unofficial
 MOZ_OFFICIAL_BRANDING_DIRECTORY=browser/branding/official

--- a/embedding/ios/confvars.sh
+++ b/embedding/ios/confvars.sh
@@ -2,9 +2,8 @@
 # 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/.
 
 MOZ_APP_NAME=geckoembed
 MOZ_APP_DISPLAYNAME=GeckoEmbed
 MOZ_UPDATER=
 MOZ_APP_VERSION=$MOZILLA_VERSION
-MOZ_EXTENSIONS_DEFAULT=" gio"

rename from extensions/gio/moz.build
rename to netwerk/protocol/gio/moz.build

rename from extensions/gio/nsGIOProtocolHandler.cpp
rename to netwerk/protocol/gio/nsGIOProtocolHandler.cpp

--- a/old-configure.in
+++ b/old-configure.in
@@ -3566,30 +3566,16 @@ MOZ_ARG_ENABLE_STRING(extensions,
         option=`echo $option | sed 's/^-//'`
         MOZ_EXTENSIONS=`echo "$MOZ_EXTENSIONS" | sed "s/ ${option}//"`
     else
         MOZ_EXTENSIONS="$MOZ_EXTENSIONS $option"
     fi
 done],
     MOZ_EXTENSIONS="$MOZ_EXTENSIONS_DEFAULT")
 
-if test -z "$MOZ_ENABLE_GIO" -a `echo "$MOZ_EXTENSIONS" | grep -c gio` -ne 0; then
-    # Suppress warning on non-X11 platforms
-    if test -n "$MOZ_X11"; then
-        AC_MSG_WARN([Removing gio from MOZ_EXTENSIONS due to --disable-gio.])
-    fi
-    MOZ_EXTENSIONS=`echo $MOZ_EXTENSIONS | sed -e 's|gio||'`
-fi
-
-if test `echo "$MOZ_EXTENSIONS" | grep -c gio` -ne 0; then
-    MOZ_GIO_COMPONENT=1
-    MOZ_EXTENSIONS=`echo $MOZ_EXTENSIONS | sed -e 's|gio||'`
-fi
-AC_SUBST(MOZ_GIO_COMPONENT)
-
 dnl Ensure every extension exists, to avoid mostly-inscrutable error messages
 dnl when trying to build a nonexistent extension.
 for extension in $MOZ_EXTENSIONS; do
     if test ! -d "${srcdir}/extensions/${extension}"; then
         AC_MSG_ERROR([Unrecognized extension provided to --enable-extensions: ${extension}.])
     fi
 done
 

--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -116,18 +116,18 @@ set_config('L10NBASEDIR', l10n_base)
 # config.guess, which we want to avoid. Even better, we could actually set
 # `choices` depending on the target, but that doesn't pan out for the same
 # reason.
 option('--enable-default-toolkit', nargs=1,
        choices=('cairo-windows', 'cairo-gtk3', 'cairo-cocoa', 'cairo-uikit',
                 'cairo-android', 'cairo-gonk'),
        help='Select default toolkit')
 
-@depends('--enable-default-toolkit', target)
-def toolkit(value, target):
+@depends('--enable-default-toolkit', target, '--help')
+def toolkit(value, target, _):
     # Define possible choices for each platform. The default is the first one
     # listed when there are several.
     os = target.os
     if target.os == 'WINNT':
         platform_choices = ('cairo-windows',)
     elif target.os == 'OSX':
         platform_choices = ('cairo-cocoa',)
     elif target.os == 'iOS':
@@ -808,23 +808,24 @@ option('--enable-ipdl-tests', help='Enab
 
 set_config('MOZ_IPDL_TESTS',
            depends_if('--enable-ipdl-tests')(lambda _: True))
 
 include('nss.configure')
 
 # Network protocol support
 # ==============================================================
-@depends(check_build_environment, '--help')
+@depends(check_build_environment, toolkit_gtk, '--help')
 @imports('os')
 @imports(_from='__builtin__', _import='sorted')
-def all_necko_protocols(build_env, _):
+def all_necko_protocols(build_env, toolkit_gtk, _):
     basedir = os.path.join(build_env.topsrcdir, 'netwerk', 'protocol')
     return tuple(sorted(p for p in os.listdir(basedir)
-                        if os.path.isdir(os.path.join(basedir, p))))
+                        if (os.path.isdir(os.path.join(basedir, p)) and
+                            (p != 'gio' or toolkit_gtk))))
 
 default_necko_protocols = all_necko_protocols
 
 @deprecated_option('--enable-necko-protocols', nargs='*')
 def necko_protocols(protocols):
     return protocols
 
 @depends(necko_protocols, default_necko_protocols)

--- a/toolkit/toolkit.mozbuild
+++ b/toolkit/toolkit.mozbuild
@@ -134,19 +134,16 @@ if CONFIG['MOZ_PREF_EXTENSIONS']:
 DIRS += [
     '/devtools',
     '/services',
     '/startupcache',
     '/js/ductwork/debugger',
     '/other-licenses/snappy',
 ]
 
-if CONFIG['MOZ_GIO_COMPONENT']:
-    DIRS += ['/extensions/gio']
-
 if CONFIG['MOZ_RUST']:
     DIRS += [
         '/toolkit/library/gtest/rust',
         '/toolkit/library/rust',
     ]
 
 DIRS += [
     '/toolkit/library/StaticXULComponentsEnd',