Recognize json media types as (non-image) mime types.

net/base/mime_util.cc

 // Copyright (c) 2012 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 <algorithm>
 #include <iterator>
 #include <map>
 #include <string>
 
 #include "base/containers/hash_tables.h"
@@ skipping 500 matching lines @@
   return image_map_.find(mime_type) != image_map_.end();
 }
 
 bool MimeUtil::IsSupportedMediaMimeType(const std::string& mime_type) const {
   return media_map_.find(mime_type) != media_map_.end();
 }
 
 bool MimeUtil::IsSupportedNonImageMimeType(const std::string& mime_type) const {
   return non_image_map_.find(mime_type) != non_image_map_.end() ||
       (mime_type.compare(0, 5, "text/") == 0 &&
-       !IsUnsupportedTextMimeType(mime_type));
+       !IsUnsupportedTextMimeType(mime_type)) ||
+      (mime_type.compare(0, 12, "application/") == 0 &&
+       MatchesMimeType("application/*+json", mime_type));

[abarth-chromium, 2013/12/01 23:02:32]

Is this how we check for +xml as well?

[sof, 2013/12/02 06:28:58]

Good question; there is no generic check for "xml media types" (i.e.,
application/ subtypes), but a few of the common ones are enumerated.
application/rss+xml is listed, but not application/soap+xml, for instance.

Beyond this part..should something with a MIME type application/rss+xml render
as text, or xml?

 }
 
 bool MimeUtil::IsUnsupportedTextMimeType(const std::string& mime_type) const {
   return unsupported_text_map_.find(mime_type) != unsupported_text_map_.end();
 }
 
 bool MimeUtil::IsSupportedJavascriptMimeType(
     const std::string& mime_type) const {
   return javascript_map_.find(mime_type) != javascript_map_.end();
 }
@@ skipping 483 matching lines @@
   post_data->append("\r\n" + value + "\r\n");
 }
 
 void AddMultipartFinalDelimiterForUpload(const std::string& mime_boundary,
                                          std::string* post_data) {
   DCHECK(post_data);
   post_data->append("--" + mime_boundary + "--\r\n");
 }
 
 }  // namespace net