Deprecate fetching stylesheets with unsupported type

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

Index: third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp b/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
index 148eba27bca841209b44c02459e4d5a4ceb6849d..dff20833b7610beecd6f8d17b9d995fc3733e671 100644
--- a/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
@@ -126,6 +126,11 @@ static LinkEventSender& linkLoadEventSender()
     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());
@@ -701,6 +706,9 @@ void LinkStyle::process()
     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()) {