Don't use SVG resource documents with an unrecognized MIME-type

third_party/WebKit/Source/core/fetch/Resource.cpp

Index: third_party/WebKit/Source/core/fetch/Resource.cpp
diff --git a/third_party/WebKit/Source/core/fetch/Resource.cpp b/third_party/WebKit/Source/core/fetch/Resource.cpp
index fb32fc9cb99bbfe20480f148aad71201944379dc..19e960e4c0fb25c4855fcf5bbec6aadc3525b6bb 100644
--- a/third_party/WebKit/Source/core/fetch/Resource.cpp
+++ b/third_party/WebKit/Source/core/fetch/Resource.cpp
@@ -35,6 +35,7 @@
 #include "platform/Logging.h"
 #include "platform/SharedBuffer.h"
 #include "platform/TraceEvent.h"
+#include "platform/network/HTTPParsers.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebProcessMemoryDump.h"
@@ -318,6 +319,11 @@ void Resource::finish()
         m_status = Cached;
 }
 
+AtomicString Resource::httpContentType() const
+{
+    return extractMIMETypeFromMediaType(m_response.httpHeaderField(HTTPNames::Content_Type)).lower();

[Mike West, 2016/02/24 13:23:44]

Would you mind adding some unit tests for this method (maybe in
`HTTPParserTest.cpp`)? It doesn't look like we're actually testing the result of
extractMIMETypeFromMediaType anywhere (sorry!).

Also, we should probably call `lower()` on the header value rather than the
result of the extraction so that we don't construct more AtomicStrings than we
need to. I also wonder whether the extraction function should be taking care of
lowering for us.

[fs, 2016/02/24 17:04:59]

Not sure if there was anything in particular you wanted me to test, so I just
did a "monkey read code, monkey write unit-test" routine.
Done. (Since it's "AtomicString in, AtomicString out" I'm not sure it makes much
of a difference though?)
I guess it could make sense - looking at the current users the majority either
does .lower() (before or after) or use equalIgnoringCase. I only see one of the
uses that doesn't (NetworkResourcesData::responseReceived), but it probably
wouldn't hurt there either. I can do that as a follow-up if you like.

+}
+
 bool Resource::passesAccessControlCheck(SecurityOrigin* securityOrigin) const
 {
     String ignoredErrorDescription;