Nuke custom factory providers.

tools/dom/templates/html/dart2js/factoryprovider_Blob.darttemplate

Index: tools/dom/templates/html/dart2js/factoryprovider_Blob.darttemplate
diff --git a/tools/dom/templates/html/dart2js/factoryprovider_Blob.darttemplate b/tools/dom/templates/html/dart2js/factoryprovider_Blob.darttemplate
deleted file mode 100644
index 620d195a6000aa8739d3ffc0584990385715501f..0000000000000000000000000000000000000000
--- a/tools/dom/templates/html/dart2js/factoryprovider_Blob.darttemplate
+++ /dev/null
@@ -1,18 +0,0 @@
-  static Blob _create([List blobParts = null, String type, String endings]) {
-    // TODO: validate that blobParts is a JS Array and convert if not.
-    // TODO: any coercions on the elements of blobParts, e.g. coerce a typed
-    // array to ArrayBuffer if it is a total view.
-    if (type == null && endings == null) {
-      return _create_1(blobParts);
-    }
-    var bag = _create_bag();
-    if (type != null) _bag_set(bag, 'type', type);
-    if (endings != null) _bag_set(bag, 'endings', endings);
-    return _create_2(blobParts, bag);
-  }
-
-  static _create_1(parts) => JS('Blob', 'new Blob(#)', parts);
-  static _create_2(parts, bag) => JS('Blob', 'new Blob(#, #)', parts, bag);
-
-  static _create_bag() => JS('var', '{}');
-  static _bag_set(bag, key, value) { JS('void', '#[#] = #', bag, key, value); }