Update mojo's WebMimeRegistry for supportsImagePrefixed

mojo/services/html_viewer/webmimeregistry_impl.cc

 // Copyright 2014 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 "mojo/services/html_viewer/webmimeregistry_impl.h"
 
 #include "base/files/file_path.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 18 matching lines @@
 }
 
 blink::WebMimeRegistry::SupportsType WebMimeRegistryImpl::supportsImageMIMEType(
     const blink::WebString& mime_type) {
   return net::IsSupportedImageMimeType(ToASCIIOrEmpty(mime_type)) ?
       blink::WebMimeRegistry::IsSupported :
       blink::WebMimeRegistry::IsNotSupported;
 }
 
 blink::WebMimeRegistry::SupportsType
+WebMimeRegistryImpl::supportsImagePrefixedMIMEType(
+    const blink::WebString& mime_type) {
+  std::string ascii_mime_type = ToASCIIOrEmpty(mime_type);
+  return (net::IsSupportedImageMimeType(ascii_mime_type) ||
+          (StartsWithASCII(ascii_mime_type, "image/", true) &&
+           net::IsSupportedNonImageMimeType(ascii_mime_type)))
+             ? WebMimeRegistry::IsSupported
+             : WebMimeRegistry::IsNotSupported;
+}
+
+blink::WebMimeRegistry::SupportsType
     WebMimeRegistryImpl::supportsJavaScriptMIMEType(
     const blink::WebString& mime_type) {
   return net::IsSupportedJavascriptMimeType(ToASCIIOrEmpty(mime_type)) ?
       blink::WebMimeRegistry::IsSupported :
       blink::WebMimeRegistry::IsNotSupported;
 }
 
 blink::WebMimeRegistry::SupportsType WebMimeRegistryImpl::supportsMediaMIMEType(
     const blink::WebString& mime_type,
     const blink::WebString& codecs,
@@ skipping 37 matching lines @@
   return blink::WebString();
 }
 
 blink::WebString WebMimeRegistryImpl::mimeTypeFromFile(
     const blink::WebString& file_path) {
   NOTIMPLEMENTED();
   return blink::WebString();
 }
 
 }  // namespace mojo