--- a/dom/media/eme/MediaKeySystemAccess.cpp
+++ b/dom/media/eme/MediaKeySystemAccess.cpp
@@ -273,61 +273,61 @@ MediaKeySystemAccess::GetKeySystemStatus
   if (aKeySystem.EqualsLiteral("org.w3.clearkey")) {
     if (!Preferences::GetBool("media.eme.clearkey.enabled", true)) {
       aOutMessage = NS_LITERAL_CSTRING("ClearKey was disabled");
       return MediaKeySystemStatus::Cdm_disabled;
     }
     return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
   }
 
-#ifdef MOZ_ADOBE_EME
-  if (aKeySystem.EqualsLiteral("com.adobe.primetime")) {
-    if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
-      aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
-      return MediaKeySystemStatus::Cdm_disabled;
-    }
+  if (Preferences::GetBool("media.gmp-eme-adobe.visible", false)) {
+    if (aKeySystem.EqualsLiteral("com.adobe.primetime")) {
+      if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
 #ifdef XP_WIN
-    // Win Vista and later only.
-    if (!IsVistaOrLater()) {
-      aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Adobe EME");
-      return MediaKeySystemStatus::Cdm_not_supported;
-    }
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Adobe EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
 #endif
 #ifdef XP_MACOSX
-    if (!nsCocoaFeatures::OnLionOrLater()) {
-      aOutMessage = NS_LITERAL_CSTRING("Minimum MacOSX version (10.7) not met for Adobe EME");
-      return MediaKeySystemStatus::Cdm_not_supported;
+      if (!nsCocoaFeatures::OnLionOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum MacOSX version (10.7) not met for Adobe EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
+#endif
+      return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
     }
-#endif
-    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
   }
-#endif
 
-#ifdef MOZ_WIDEVINE_EME
-  if (aKeySystem.EqualsLiteral("com.widevine.alpha")) {
+  if (Preferences::GetBool("media.gmp-widevinecdm.visible", false)) {
+    if (aKeySystem.EqualsLiteral("com.widevine.alpha")) {
 #ifdef XP_WIN
-    // Win Vista and later only.
-    if (!IsVistaOrLater()) {
-      aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Widevine EME");
-      return MediaKeySystemStatus::Cdm_not_supported;
-    }
+      // Win Vista and later only.
+      if (!IsVistaOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version (Vista) not met for Widevine EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
 #endif
 #ifdef XP_MACOSX
-    if (!nsCocoaFeatures::OnLionOrLater()) {
-      aOutMessage = NS_LITERAL_CSTRING("Minimum MacOSX version (10.7) not met for Widevine EME");
-      return MediaKeySystemStatus::Cdm_not_supported;
-    }
+      if (!nsCocoaFeatures::OnLionOrLater()) {
+        aOutMessage = NS_LITERAL_CSTRING("Minimum MacOSX version (10.7) not met for Widevine EME");
+        return MediaKeySystemStatus::Cdm_not_supported;
+      }
 #endif
-    if (!Preferences::GetBool("media.gmp-widevinecdm.enabled", false)) {
-      aOutMessage = NS_LITERAL_CSTRING("Widevine EME disabled");
-      return MediaKeySystemStatus::Cdm_disabled;
+      if (!Preferences::GetBool("media.gmp-widevinecdm.enabled", false)) {
+        aOutMessage = NS_LITERAL_CSTRING("Widevine EME disabled");
+        return MediaKeySystemStatus::Cdm_disabled;
+      }
+      return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
     }
-    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
   }
-#endif
 
   return MediaKeySystemStatus::Cdm_not_supported;
 }
 
 static bool
 GMPDecryptsAndDecodesAAC(mozIGeckoMediaPluginService* aGMPS,
                          const nsAString& aKeySystem,
                          DecoderDoctorDiagnostics* aDiagnostics)

--- a/dom/media/eme/moz.build
+++ b/dom/media/eme/moz.build
@@ -1,17 +1,14 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # 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/.
 
-for cdm in CONFIG['MOZ_EME_MODULES']:
-    DEFINES['MOZ_%s_EME' % cdm.upper()] = True
-
 EXPORTS.mozilla.dom += [
     'MediaEncryptedEvent.h',
     'MediaKeyError.h',
     'MediaKeyMessageEvent.h',
     'MediaKeys.h',
     'MediaKeySession.h',
     'MediaKeyStatusMap.h',
     'MediaKeySystemAccess.h',

--- a/dom/media/gmp/GMPChild.cpp
+++ b/dom/media/gmp/GMPChild.cpp
@@ -18,19 +18,17 @@
 #include "gmp-video-decode.h"
 #include "gmp-video-encode.h"
 #include "GMPPlatform.h"
 #include "mozilla/dom/CrashReporterChild.h"
 #include "mozilla/ipc/ProcessChild.h"
 #include "GMPUtils.h"
 #include "prio.h"
 #include "base/task.h"
-#ifdef MOZ_WIDEVINE_EME
 #include "widevine-adapter/WidevineAdapter.h"
-#endif
 
 using namespace mozilla::ipc;
 using mozilla::dom::CrashReporterChild;
 
 static const int MAX_VOUCHER_LENGTH = 500000;
 
 #ifdef XP_WIN
 #include <stdlib.h> // for _exit()
@@ -371,40 +369,30 @@ GMPChild::AnswerStartPlugin(const nsStri
 
   mGMPLoader = GMPProcessChild::GetGMPLoader();
   if (!mGMPLoader) {
     NS_WARNING("Failed to get GMPLoader");
     delete platformAPI;
     return false;
   }
 
-#ifdef MOZ_WIDEVINE_EME
   bool isWidevine = aAdapter.EqualsLiteral("widevine");
-#endif
-
 #if defined(MOZ_GMP_SANDBOX) && defined(XP_MACOSX)
   MacSandboxPluginType pluginType = MacSandboxPluginType_GMPlugin_Default;
-#ifdef MOZ_WIDEVINE_EME
   if (isWidevine) {
-      pluginType = MacSandboxPluginType_GMPlugin_EME_Widevine;
+    pluginType = MacSandboxPluginType_GMPlugin_EME_Widevine;
   }
-#endif
   if (!SetMacSandboxInfo(pluginType)) {
     NS_WARNING("Failed to set Mac GMP sandbox info");
     delete platformAPI;
     return false;
   }
 #endif
 
-  GMPAdapter* adapter = nullptr;
-#ifdef MOZ_WIDEVINE_EME
-  if (isWidevine) {
-    adapter = new WidevineAdapter();
-  }
-#endif
+  GMPAdapter* adapter = (isWidevine) ? new WidevineAdapter() : nullptr;
   if (!mGMPLoader->Load(libPath.get(),
                         libPath.Length(),
                         mNodeId.BeginWriting(),
                         mNodeId.Length(),
                         platformAPI,
                         adapter)) {
     NS_WARNING("Failed to load GMP");
     delete platformAPI;

--- a/dom/media/gmp/GMPParent.cpp
+++ b/dom/media/gmp/GMPParent.cpp
@@ -35,20 +35,18 @@ using CrashReporter::GetIDFromMinidump;
 #endif
 
 #include "mozilla/Telemetry.h"
 
 #ifdef XP_WIN
 #include "WMFDecoderModule.h"
 #endif
 
-#ifdef MOZ_WIDEVINE_EME
 #include "mozilla/dom/WidevineCDMManifestBinding.h"
 #include "widevine-adapter/WidevineAdapter.h"
-#endif
 
 namespace mozilla {
 
 #undef LOG
 #undef LOGD
 
 extern LogModule* GetGMPLog();
 #define LOG(level, x, ...) MOZ_LOG(GetGMPLog(), (level), (x, ##__VA_ARGS__))
@@ -804,28 +802,24 @@ GMPParent::ReadGMPMetaData()
     return GenericPromise::CreateAndReject(rv, __func__);
   }
   infoFile->AppendRelativePath(mName + NS_LITERAL_STRING(".info"));
 
   if (FileExists(infoFile)) {
     return ReadGMPInfoFile(infoFile);
   }
 
-#ifdef MOZ_WIDEVINE_EME
   // Maybe this is the Widevine adapted plugin?
   nsCOMPtr<nsIFile> manifestFile;
   rv = mDirectory->Clone(getter_AddRefs(manifestFile));
   if (NS_FAILED(rv)) {
     return GenericPromise::CreateAndReject(rv, __func__);
   }
   manifestFile->AppendRelativePath(NS_LITERAL_STRING("manifest.json"));
   return ReadChromiumManifestFile(manifestFile);
-#else
-  return GenericPromise::CreateAndReject(rv, __func__);
-#endif
 }
 
 RefPtr<GenericPromise>
 GMPParent::ReadGMPInfoFile(nsIFile* aFile)
 {
   GMPInfoFileParser parser;
   if (!parser.Init(aFile)) {
     return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
@@ -910,17 +904,16 @@ GMPParent::ReadGMPInfoFile(nsIFile* aFil
 
   if (mCapabilities.IsEmpty()) {
     return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
   }
 
   return GenericPromise::CreateAndResolve(true, __func__);
 }
 
-#ifdef MOZ_WIDEVINE_EME
 RefPtr<GenericPromise>
 GMPParent::ReadChromiumManifestFile(nsIFile* aFile)
 {
   nsAutoCString json;
   if (!ReadIntoString(aFile, json, 5 * 1024)) {
     return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
   }
 
@@ -963,17 +956,16 @@ GMPParent::ParseChromiumManifest(nsStrin
   MOZ_ASSERT(mName.EqualsLiteral("widevinecdm"));
   mAdapter = NS_LITERAL_STRING("widevine");
 #ifdef XP_WIN
   mLibs = NS_LITERAL_CSTRING("dxva2.dll");
 #endif
 
   return GenericPromise::CreateAndResolve(true, __func__);
 }
-#endif
 
 bool
 GMPParent::CanBeSharedCrossNodeIds() const
 {
   return !mAsyncShutdownInProgress &&
          mNodeId.IsEmpty() &&
          // XXX bug 1159300 hack -- maybe remove after openh264 1.4
          // We don't want to use CDM decoders for non-encrypted playback

--- a/dom/media/gmp/GMPParent.h
+++ b/dom/media/gmp/GMPParent.h
@@ -162,20 +162,18 @@ public:
 
 private:
   ~GMPParent();
 
   RefPtr<GeckoMediaPluginServiceParent> mService;
   bool EnsureProcessLoaded();
   RefPtr<GenericPromise> ReadGMPMetaData();
   RefPtr<GenericPromise> ReadGMPInfoFile(nsIFile* aFile);
-#ifdef MOZ_WIDEVINE_EME
   RefPtr<GenericPromise> ParseChromiumManifest(nsString aJSON); // Main thread.
   RefPtr<GenericPromise> ReadChromiumManifestFile(nsIFile* aFile); // GMP thread.
-#endif
 #ifdef MOZ_CRASHREPORTER
   void WriteExtraDataForMinidump(CrashReporter::AnnotationTable& notes);
   void GetCrashID(nsString& aResult);
 #endif
   void ActorDestroy(ActorDestroyReason aWhy) override;
 
   PCrashReporterParent* AllocPCrashReporterParent(const NativeThreadId& aThread) override;
   bool DeallocPCrashReporterParent(PCrashReporterParent* aCrashReporter) override;

--- a/dom/media/gmp/moz.build
+++ b/dom/media/gmp/moz.build
@@ -1,17 +1,14 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # 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/.
 
-for cdm in CONFIG['MOZ_EME_MODULES']:
-    DEFINES['MOZ_%s_EME' % cdm.upper()] = True
-
 XPIDL_MODULE = 'content_geckomediaplugins'
 
 XPIDL_SOURCES += [
     'mozIGeckoMediaPluginChromeService.idl',
     'mozIGeckoMediaPluginService.idl',
 ]
 
 EXPORTS += [
@@ -115,23 +112,19 @@ UNIFIED_SOURCES += [
     'GMPVideoEncoderParent.cpp',
     'GMPVideoHost.cpp',
     'GMPVideoi420FrameImpl.cpp',
     'GMPVideoPlaneImpl.cpp',
 ]
 
 DIRS += [
     'rlz',
+    'widevine-adapter',
 ]
 
-if 'widevine' in CONFIG['MOZ_EME_MODULES']:
-  DIRS += [
-      'widevine-adapter',
-  ]
-
 IPDL_SOURCES += [
   'GMPTypes.ipdlh',
   'PGMP.ipdl',
   'PGMPAudioDecoder.ipdl',
   'PGMPContent.ipdl',
   'PGMPDecryptor.ipdl',
   'PGMPService.ipdl',
   'PGMPStorage.ipdl',