Remove BLOB conditional.

tools/dom/idl/dart/dart.idl

 // This file introduces / supplements and forces Dart declarations.
 
 [Supplemental,
  Constructor]
 interface AudioContext {};
 
 [Supplemental]
 interface Document {
   [Suppressed] DOMObject getCSSCanvasContext(in DOMString contextId, in DOMString name, in long width, in long height);
   CanvasRenderingContext getCSSCanvasContext(in DOMString contextId, in DOMString name, in long width, in long height);
@@ skipping 325 matching lines @@
 };
 
 [Supplemental]
 interface XMLHttpRequest {
    [Custom] void send()
        raises(DOMException);
    [Custom] void send(in ArrayBuffer data) // FIXME: this should be eventually deprecated.
        raises(DOMException);
    [Custom] void send(in ArrayBufferView data)
        raises(DOMException);
-   [Conditional=BLOB, Custom] void send(in Blob data)
+   [Custom] void send(in Blob data)
        raises(DOMException);
    [Custom] void send(in Document data)
        raises(DOMException);
    [Custom] void send([StrictTypeChecking] in DOMString data)
        raises(DOMException);
    [Custom] void send(in DOMFormData data)
        raises(DOMException);
 };
 
 
@@ skipping 16 matching lines @@
 [Suppressed]
 interface ScriptProfile {};
 
 
 [Suppressed]
 interface ScriptProfileNode {};
 
 
 [Suppressed]
 interface Entity {};