html_viewer: Implement various mime utilities.

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 93 matching lines @@
 blink::WebMimeRegistry::SupportsType
     WebMimeRegistryImpl::supportsNonImageMIMEType(
     const blink::WebString& mime_type) {
   return net::IsSupportedNonImageMimeType(ToASCIIOrEmpty(mime_type)) ?
       blink::WebMimeRegistry::IsSupported :
       blink::WebMimeRegistry::IsNotSupported;
 }
 
 blink::WebString WebMimeRegistryImpl::mimeTypeForExtension(
     const blink::WebString& file_extension) {
-  NOTIMPLEMENTED();
-  return blink::WebString();
+  std::string mime_type;
+  net::GetMimeTypeFromExtension(
+      base::FilePath::FromUTF16Unsafe(file_extension).value(), &mime_type);
+  return blink::WebString::fromUTF8(mime_type);
 }
 
 blink::WebString WebMimeRegistryImpl::wellKnownMimeTypeForExtension(
     const blink::WebString& file_extension) {
-  NOTIMPLEMENTED();
-  return blink::WebString();
+  std::string mime_type;
+  net::GetWellKnownMimeTypeFromExtension(
+      base::FilePath::FromUTF16Unsafe(file_extension).value(), &mime_type);
+  return blink::WebString::fromUTF8(mime_type);
 }
 
 blink::WebString WebMimeRegistryImpl::mimeTypeFromFile(
     const blink::WebString& file_path) {
-  NOTIMPLEMENTED();
-  return blink::WebString();
+  std::string mime_type;
+  net::GetMimeTypeFromFile(base::FilePath::FromUTF16Unsafe(file_path),
+                           &mime_type);
+  return blink::WebString::fromUTF8(mime_type);
 }
 
 }  // namespace html_viewer