Add deprecation warning for script fetches with invalid types

third_party/WebKit/Source/core/frame/Deprecation.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/Deprecation.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/frame/FrameConsole.h"
 #include "core/frame/FrameHost.h"
@@ skipping 363 matching lines @@
 
     case UseCounter::V8SVGSVGElement_CurrentView_AttributeGetter:
         return willBeRemoved("SVGSVGElement.currentView", 56, "4511711998509056");
 
     case UseCounter::V8SVGSVGElement_Viewport_AttributeGetter:
         return willBeRemoved("SVGSVGElement.viewport", 55, "5686865248124928");
 
     case UseCounter::NavigatorPointerEnabled:
         return "Navigator.pointerEnabled is a non-standard API added for experiments only. It will be removed in near future.";
 
+    case UseCounter::ScriptInvalidTypeOrLanguage:
+        return String::format("Fetching scripts with an invalid type attribute is deprecated and will be removed in %s. See https://html.spec.whatwg.org/#javascript-mime-type for a list of valid types.", milestoneString(56));
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();
     }
 }
 
 } // namespace blink