diff --git a/content/base/src/nsContentUtils.cpp b/content/base/src/nsContentUtils.cpp
index 3d7630ba2157..a5cbbee76d6a 100644
--- a/content/base/src/nsContentUtils.cpp
+++ b/content/base/src/nsContentUtils.cpp
@@ -6380,6 +6380,16 @@ nsContentUtils::FindInternalContentViewer(const char* aType,
   }
 #endif
 
+#ifdef MOZ_DASH
+  if (DecoderTraits::IsDASHMPDType(nsDependentCString(aType))) {
+    docFactory = do_GetService("@mozilla.org/content/document-loader-factory;1");
+    if (docFactory && aLoaderType) {
+      *aLoaderType = TYPE_CONTENT;
+    }
+    return docFactory.forget();
+  }
+#endif
+
 #ifdef MOZ_GSTREAMER
   if (DecoderTraits::IsGStreamerSupportedType(nsDependentCString(aType))) {
     docFactory = do_GetService("@mozilla.org/content/document-loader-factory;1");
diff --git a/content/media/test/manifest.js b/content/media/test/manifest.js
index fc6578d79616..bc4ecb813303 100644
--- a/content/media/test/manifest.js
+++ b/content/media/test/manifest.js
@@ -27,6 +27,7 @@ var gProgressTests = [
   { name:"320x240.ogv", type:"video/ogg", width:320, height:240, duration:0.266, size:28942 },
   { name:"seek.webm", type:"video/webm", duration:3.966, size:215529 },
   { name:"gizmo.mp4", type:"video/mp4", duration:5.56, size:383631 },
+  { name:"dash-manifest.mpd", type:"application/dash+xml", duration:3.966 },
   { name:"bogus.duh", type:"bogus/duh" }
 ];
 
@@ -255,6 +256,12 @@ var gInfoLeakTests = [
   }, {
     type: 'video/webm',
     src: fileUriToSrc("tests/content/media/test/404.webm", false),
+  }, {
+    type: 'application/dash+xml',
+    src: fileUriToSrc("tests/content/media/test/dash-manifest.mpd", true),
+  }, {
+    type: 'application/dash+xml',
+    src: fileUriToSrc("tests/content/media/test/404.mpd", false),
   }, {
     type: 'video/ogg',
     src: 'http://localhost/404.ogv',
@@ -264,6 +271,9 @@ var gInfoLeakTests = [
   }, {
     type: 'video/webm',
     src: 'http://localhost/404.webm',
+  }, {
+    type: 'application/dash+xml',
+    src: 'http://localhost/404.mpd',
   }, {
     type: 'video/ogg',
     src: 'http://example.com/tests/content/media/test/test_info_leak.html'
diff --git a/content/media/test/test_info_leak.html b/content/media/test/test_info_leak.html
index d37b236c107d..cedf1fcfb03c 100644
--- a/content/media/test/test_info_leak.html
+++ b/content/media/test/test_info_leak.html
@@ -81,7 +81,7 @@ function listener(evt) {
 }
 
 function createMedia(type, src, token) {
-  var tag = /^video/.test(type) ? "video" : "audio";
+  var tag = getMajorMimeType(test.type);
   var v = document.createElement(tag);
   for (var i=0; i<gEventTypes.length; i++) {
     v.addEventListener(gEventTypes[i], listener, false);
diff --git a/content/media/test/test_seekable1.html b/content/media/test/test_seekable1.html
index 9ca054781335..900d9faec9de 100644
--- a/content/media/test/test_seekable1.html
+++ b/content/media/test/test_seekable1.html
@@ -50,7 +50,7 @@ function createTestArray() {
 }
 
 function startTest(test, token) {
-  var elemType = /^audio/.test(test.type) ? "audio" : "video";
+  var elemType = getMajorMimeType(test.type);
   var element = document.createElement(elemType);
   element.src = test.name;
   element.token = token;
diff --git a/content/media/test/test_standalone.html b/content/media/test/test_standalone.html
index 15206657ddba..65733a19f07c 100644
--- a/content/media/test/test_standalone.html
+++ b/content/media/test/test_standalone.html
@@ -18,8 +18,8 @@ for (var i=0; i<gSmallTests.length; ++i) {
 
   // We can't play WAV files in stand alone documents, so just don't
   // run the test on non-video content types.
-  var isVideo = /^video/.test(test.type) ? true : false;
-  if (!isVideo || !document.createElement("video").canPlayType(test.type))
+  var tag = getMajorMimeType(test.type);
+  if (tag != "video" || !document.createElement("video").canPlayType(test.type))
     continue;
   
   var f = document.createElement("iframe");
diff --git a/layout/build/nsContentDLF.h b/layout/build/nsContentDLF.h
index 8bc0a23f6bce..87f5ab2241d3 100644
--- a/layout/build/nsContentDLF.h
+++ b/layout/build/nsContentDLF.h
@@ -64,6 +64,13 @@ NS_NewContentDocumentLoaderFactory(nsIDocumentLoaderFactory** aResult);
 #define CONTENTDLF_WEBM_CATEGORIES
 #endif
 
+#ifdef MOZ_DASH
+#define CONTENTDLF_DASH_CATEGORIES \
+    { "Gecko-Content-Viewers", APPLICATION_DASH, "@mozilla.org/content/document-loader-factory;1" },
+#else
+#define CONTENTDLF_DASH_CATEGORIES
+#endif
+
 #define CONTENTDLF_CATEGORIES \
     { "Gecko-Content-Viewers", TEXT_HTML, "@mozilla.org/content/document-loader-factory;1" }, \
     { "Gecko-Content-Viewers", TEXT_PLAIN, "@mozilla.org/content/document-loader-factory;1" }, \
@@ -85,7 +92,9 @@ NS_NewContentDocumentLoaderFactory(nsIDocumentLoaderFactory** aResult);
     { "Gecko-Content-Viewers", VIEWSOURCE_CONTENT_TYPE, "@mozilla.org/content/document-loader-factory;1" }, \
     { "Gecko-Content-Viewers", IMAGE_SVG_XML, "@mozilla.org/content/document-loader-factory;1" }, \
     { "Gecko-Content-Viewers", APPLICATION_MATHML_XML, "@mozilla.org/content/document-loader-factory;1" }, \
-    CONTENTDLF_WEBM_CATEGORIES
+    CONTENTDLF_WEBM_CATEGORIES \
+    CONTENTDLF_DASH_CATEGORIES
+
 
 #endif