Always set the Document::contentType attribute in ScriptThread::load().

There's no good reason to limit this to a few particular content types.

components/script/script_thread.rs

@@ -1718,15 +1718,9 @@ impl ScriptThread {
             headers.get().map(|&LastModified(HttpDate(ref tm))| dom_last_modified(tm))
         });
 
-        let content_type = metadata.content_type.as_ref().and_then(|&Serde(ContentType(ref mimetype))| {
+        let content_type = metadata.content_type
-            match *mimetype {
+                                   .as_ref()
-                Mime(TopLevel::Application, SubLevel::Xml, _) |
+                                   .map(|&Serde(ContentType(ref mimetype))| DOMString::from(mimetype.to_string()));
-                Mime(TopLevel::Application, SubLevel::Ext(_), _) |
-                Mime(TopLevel::Text, SubLevel::Xml, _) |
-                Mime(TopLevel::Text, SubLevel::Plain, _) => Some(DOMString::from(mimetype.to_string())),
-                _ => None,
-            }
-        });
 
         let loader = DocumentLoader::new_with_threads(self.resource_threads.clone(),
                                                       Some(final_url.clone()));

tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_bmp.html.ini

@@ -1,5 +0,0 @@
-[contenttype_bmp.html]
-  type: testharness
-  [BMP document.contentType === 'image/bmp']
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_css.html.ini

@@ -1,5 +0,0 @@
-[contenttype_css.html]
-  type: testharness
-  [CSS document.contentType === 'text/css']
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_gif.html.ini

@@ -1,5 +0,0 @@
-[contenttype_gif.html]
-  type: testharness
-  [GIF document.contentType === 'image/gif']
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_jpg.html.ini

@@ -1,5 +0,0 @@
-[contenttype_jpg.html]
-  type: testharness
-  [JPG document.contentType === 'image/jpeg']
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Document-contentType/contentType/contenttype_png.html.ini

@@ -1,5 +0,0 @@
-[contenttype_png.html]
-  type: testharness
-  [PNG document.contentType === 'image/png']
-    expected: FAIL
-

tests/wpt/metadata/html/browsers/browsing-the-web/read-media/pageload-image.html.ini

@@ -1,5 +0,0 @@
-[pageload-image.html]
-  type: testharness
-  [The document for a standalone media file should have one child in the body.]
-    expected: FAIL
-