diff --git a/dom/media/MediaManager.cpp b/dom/media/MediaManager.cpp
index b9324853b7de..943bd9caac04 100644
--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -122,8 +122,6 @@ using dom::MediaStreamError;
 using dom::GetUserMediaRequest;
 using dom::Sequence;
 using dom::OwningBooleanOrMediaTrackConstraints;
-using dom::SupportedAudioConstraints;
-using dom::SupportedVideoConstraints;
 using media::Pledge;
 using media::NewRunnableFrom;
 using media::NewTaskFrom;
diff --git a/dom/webidl/Constraints.webidl b/dom/webidl/Constraints.webidl
deleted file mode 100644
index f7f0c706a9d7..000000000000
--- a/dom/webidl/Constraints.webidl
+++ /dev/null
@@ -1,54 +0,0 @@
-/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* 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/.
- */
-
-// These dictionaries need to be in a separate file from their use in unions
-// in MediaTrackConstraintSet.webidl due to a webidl compiler limitation.
-
-// These enums are in the spec even though they're not used directly in the API
-// due to https://www.w3.org/Bugs/Public/show_bug.cgi?id=19936
-// Their binding code is quite useful though, and is used in the implementation.
-
-enum VideoFacingModeEnum {
-    "user",
-    "environment",
-    "left",
-    "right"
-};
-
-enum MediaSourceEnum {
-    "camera",
-    "screen",
-    "application",
-    "window",
-    "browser",
-    "microphone",
-    "audioCapture",
-    "other"
-};
-
-dictionary ConstrainLongRange {
-    long min;
-    long max;
-    long exact;
-    long ideal;
-};
-
-dictionary ConstrainDoubleRange {
-    double min;
-    double max;
-    double exact;
-    double ideal;
-};
-
-dictionary ConstrainBooleanParameters {
-    boolean exact;
-    boolean ideal;
-};
-
-dictionary ConstrainDOMStringParameters {
-    (DOMString or sequence<DOMString>) exact;
-    (DOMString or sequence<DOMString>) ideal;
-};
diff --git a/dom/webidl/MediaStreamTrack.webidl b/dom/webidl/MediaStreamTrack.webidl
index 12d8b32ebb23..69e465506ae0 100644
--- a/dom/webidl/MediaStreamTrack.webidl
+++ b/dom/webidl/MediaStreamTrack.webidl
@@ -10,6 +10,44 @@
  * liability, trademark and document use rules apply.
  */
 
+// These two enums are in the spec even though they're not used directly in the
+// API due to https://www.w3.org/Bugs/Public/show_bug.cgi?id=19936
+// Their binding code is used in the implementation.
+
+enum VideoFacingModeEnum {
+    "user",
+    "environment",
+    "left",
+    "right"
+};
+
+enum MediaSourceEnum {
+    "camera",
+    "screen",
+    "application",
+    "window",
+    "browser",
+    "microphone",
+    "audioCapture",
+    "other"
+};
+
+typedef (long or ConstrainLongRange) ConstrainLong;
+typedef (double or ConstrainDoubleRange) ConstrainDouble;
+typedef (boolean or ConstrainBooleanParameters) ConstrainBoolean;
+typedef (DOMString or sequence<DOMString> or ConstrainDOMStringParameters) ConstrainDOMString;
+
+dictionary MediaTrackConstraintSet {
+    ConstrainLong width;
+    ConstrainLong height;
+    ConstrainDouble frameRate;
+    ConstrainDOMString facingMode;
+    DOMString mediaSource = "camera";
+    long long browserWindow;
+    boolean scrollWithPage;
+    ConstrainDOMString deviceId;
+};
+
 dictionary MediaTrackConstraints : MediaTrackConstraintSet {
     sequence<MediaTrackConstraintSet> advanced;
 };
diff --git a/dom/webidl/MediaTrackConstraintSet.webidl b/dom/webidl/MediaTrackConstraintSet.webidl
index a44de9f84750..63bc6bac5da8 100644
--- a/dom/webidl/MediaTrackConstraintSet.webidl
+++ b/dom/webidl/MediaTrackConstraintSet.webidl
@@ -7,34 +7,32 @@
  * http://dev.w3.org/2011/webrtc/editor/getusermedia.html
  */
 
-enum SupportedVideoConstraints {
-    "other",
-    "facingMode",
-    "width",
-    "height",
-    "frameRate",
-    "mediaSource",
-    "browserWindow",
-    "scrollWithPage",
-    "deviceId"
+// These dictionaries need to be in a separate file from their use in unions
+// in MediaSreamTrack.webidl due to a webidl compiler limitation:
+//
+// TypeError: Dictionary contains a union that contains a dictionary in the same
+// WebIDL file.  This won't compile.  Move the inner dictionary to a different file.
+
+dictionary ConstrainLongRange {
+    long min;
+    long max;
+    long exact;
+    long ideal;
 };
 
-enum SupportedAudioConstraints {
-    "other"
+dictionary ConstrainDoubleRange {
+    double min;
+    double max;
+    double exact;
+    double ideal;
 };
 
-dictionary MediaTrackConstraintSet {
-    ConstrainLong width;
-    ConstrainLong height;
-    ConstrainDouble frameRate;
-    ConstrainDOMString facingMode;
-    DOMString mediaSource = "camera";
-    long long browserWindow;
-    boolean scrollWithPage;
-    ConstrainDOMString deviceId;
+dictionary ConstrainBooleanParameters {
+    boolean exact;
+    boolean ideal;
 };
 
-typedef (long or ConstrainLongRange) ConstrainLong;
-typedef (double or ConstrainDoubleRange) ConstrainDouble;
-typedef (boolean or ConstrainBooleanParameters) ConstrainBoolean;
-typedef (DOMString or sequence<DOMString> or ConstrainDOMStringParameters) ConstrainDOMString;
+dictionary ConstrainDOMStringParameters {
+    (DOMString or sequence<DOMString>) exact;
+    (DOMString or sequence<DOMString>) ideal;
+};
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index 6cb6a1d270b8..25f4e6260f1b 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -83,7 +83,6 @@ WEBIDL_FILES = [
     'Comment.webidl',
     'CompositionEvent.webidl',
     'Console.webidl',
-    'Constraints.webidl',
     'Contacts.webidl',
     'ContainerBoxObject.webidl',
     'ConvolverNode.webidl',