Add GetMimeTypeFromFile to Mojo's network service.

mojo/shell/local_fetcher.h

 // Copyright 2015 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.
 
 #ifndef MOJO_SHELL_LOCAL_FETCHER_H_
 #define MOJO_SHELL_LOCAL_FETCHER_H_
 
+#include <string>
+
 #include "base/files/file_path.h"
-#include "mojo/services/network/public/interfaces/url_loader.mojom.h"
 #include "mojo/shell/fetcher.h"
 #include "url/gurl.h"
 
 namespace mojo {
+
+class NetworkService;
+
 namespace shell {
 
 // Implements Fetcher for file:// URLs.
 class LocalFetcher : public Fetcher {
  public:
-  LocalFetcher(const GURL& url,
+  LocalFetcher(NetworkService* network_service,
+               const GURL& url,
                const GURL& url_without_query,
                const FetchCallback& loader_callback);
 
+  void GetMimeTypeFromFileCallback(const mojo::String& mime_type);
+
  private:
   const GURL& GetURL() const override;
   GURL GetRedirectURL() const override;
   GURL GetRedirectReferer() const override;
 
   URLResponsePtr AsURLResponse(base::TaskRunner* task_runner,
                                uint32_t skip) override;
 
   void AsPath(
       base::TaskRunner* task_runner,
       base::Callback<void(const base::FilePath&, bool)> callback) override;
 
   std::string MimeType() override;
 
   bool HasMojoMagic() override;
 
   bool PeekFirstLine(std::string* line) override;
 
   GURL url_;
   base::FilePath path_;
+  std::string mime_type_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalFetcher);
 };
 
 }  // namespace shell
+
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_LOCAL_FETCHER_H_