mediaview: Mount ARC documents provider file system volumes.

chrome/browser/chromeos/fileapi/file_system_backend.cc

 // Copyright 2013 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 "chrome/browser/chromeos/fileapi/file_system_backend.h"
 
 #include <stddef.h>
 
 #include <memory>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
 #include "chrome/browser/chromeos/fileapi/file_access_permissions.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend_delegate.h"
 #include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
 #include "chrome/common/url_constants.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/cros_disks_client.h"
 #include "storage/browser/fileapi/async_file_util.h"
 #include "storage/browser/fileapi/external_mount_points.h"
 #include "storage/browser/fileapi/file_stream_reader.h"
 #include "storage/browser/fileapi/file_stream_writer.h"
@@ skipping 125 matching lines @@
     if (components.size() < 2) {
       // Unable to access /archive and /removable directories directly. The
       // inner mount name must be specified.
       callback.Run(
           GURL(root_url), std::string(), base::File::FILE_ERROR_SECURITY);
       return;
     }
     std::string inner_mount_name = components[1];
     root_url += inner_mount_name + "/";
     name = inner_mount_name;
+  } else if (id == arc::kDocumentsProviderMountPointName) {
+    // For ARC documents provider file system, volumes are mounted per document
+    // provider root, so we need to fix up |root_url| to point to an individual
+    // root.
+    std::string authority;
+    std::string root_document_id;
+    base::FilePath unused_path;
+    if (!arc::ParseDocumentsProviderUrl(url, &authority, &root_document_id,
+                                        &unused_path)) {
+      callback.Run(GURL(root_url), std::string(),
+                   base::File::FILE_ERROR_SECURITY);
+      return;
+    }
+    root_url += authority + "/" + root_document_id + "/";

[mtomasz, 2017/01/11 09:35:22]

Does root_document_id need to be escaped?

[Shuhei Takahashi, 2017/01/12 08:20:28]

You're right. Done.

+    name = authority + ":" + root_document_id;
   } else {
     name = id;
   }
 
   callback.Run(GURL(root_url), name, base::File::FILE_OK);
 }
 
 storage::FileSystemQuotaUtil* FileSystemBackend::GetQuotaUtil() {
   // No quota support.
   return NULL;
@@ skipping 293 matching lines @@
     const base::FilePath& entry_path) const {
   base::FilePath virtual_path;
   if (!GetVirtualPath(entry_path, &virtual_path))
     return storage::FileSystemURL();
 
   return context->CreateCrackedFileSystemURL(
       GURL() /* origin */, storage::kFileSystemTypeExternal, virtual_path);
 }
 
 }  // namespace chromeos