Deprecate fetching stylesheets with unsupported type

third_party/WebKit/Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 108 matching lines @@
         iconSizes.append(IntSize(width, height));
     }
 }
 
 static LinkEventSender& linkLoadEventSender()
 {
     DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<LinkEventSender>, sharedLoadEventSender, (LinkEventSender::create(EventTypeNames::load)));
     return *sharedLoadEventSender;
 }
 
+static bool styleSheetTypeIsSupported(const String& type)
+{
+    return type.isEmpty() || type.contains("text/css");

[Yoav Weiss, 2016/01/18 08:21:18]

This should be a case agnostic comparison, and should use startsWith rather than
contains.

Otherwise, it'd be nice to plumb this through platform/MimeTypeRegistry and
simple_webmimregistry_impl and eventually components/mime_util/mime_util.c

I don't think it's critical to do that in current CL, and we want to push the
deprecation for 49, but maybe add a TODO and plumb everything for the next step?

[suzyh_UTC10 (ex-contributor), 2016/01/19 01:58:12]

I've plumbed it through platform/MimeTypeRegistry and used platform/ContentType,
as done in e.g. core/html/HTMLImageElement.cpp:supportedImageType. Using
platform/ContentType I understand this becomes an equality check rather than
startsWith.

+}
+
 void HTMLLinkElement::parseSizesAttribute(const AtomicString& value, Vector<IntSize>& iconSizes)
 {
     ASSERT(iconSizes.isEmpty());
     if (value.isEmpty())
         return;
     if (value.is8Bit())
         parseSizes(value.characters8(), value.length(), iconSizes);
     else
         parseSizes(value.characters16(), value.length(), iconSizes);
 }
@@ skipping 555 matching lines @@
             return;
         if (!document().contentSecurityPolicy()->allowImageFromSource(builder.url()))
             return;
         if (document().frame() && document().frame()->loader().client())
             document().frame()->loader().client()->dispatchDidChangeIcons(m_owner->relAttribute().iconType());
     }
 
     if (!m_owner->loadLink(type, as, builder.url()))
         return;
 
+    if (!styleSheetTypeIsSupported(type))
+        UseCounter::countDeprecation(document(), UseCounter::NonCSSStylesheetType);
+
     if (m_disabledState != Disabled && m_owner->relAttribute().isStyleSheet() && shouldLoadResource() && builder.url().isValid()) {
 
         if (resource()) {
             removePendingSheet();
             clearResource();
             clearFetchFollowingCORS();
         }
 
         if (!m_owner->shouldLoadLink())
             return;
@@ skipping 52 matching lines @@
         removePendingSheet();
 }
 
 DEFINE_TRACE(LinkStyle)
 {
     visitor->trace(m_sheet);
     LinkResource::trace(visitor);
 }
 
 } // namespace blink