arc: Add utility functions to implement ARC content file system

chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h

Index: chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h b/chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h
index f5e4d944b5b20ed6a7f02214435291a5362112c0..19b365ab4d8320aa70b064d68a6810a16bccf834 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h
+++ b/chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h
@@ -8,6 +8,10 @@
 #include "base/files/file_path.h"
 #include "url/gurl.h"
 
+namespace storage {
+class FileSystemURL;
+}
+
 namespace arc {
 
 // The name of the ARC content file system mount point.
@@ -16,6 +20,12 @@ extern const char kMountPointName[];
 // The path of the ARC content file system mount point.
 extern const base::FilePath::CharType kMountPointPath[];
 
+// Escapes the given ARC URL.
+std::string EscapeArcUrl(const GURL& arc_url);
+
+// Unescapes the given escaped ARC URL.
+GURL UnescapeArcUrl(const std::string& escaped_arc_url);
+
 // Converts a URL which can be used within the ARC container to an externalfile:
 // URL which can be used by Chrome.
 GURL ArcUrlToExternalFileUrl(const GURL& arc_url);
@@ -25,6 +35,9 @@ GURL ArcUrlToExternalFileUrl(const GURL& arc_url);
 // empty GURL.
 GURL ExternalFileUrlToArcUrl(const GURL& external_file_url);
 
+// Converts a FileSystemURL to a URL which can be used within the ARC container.
+GURL FileSystemUrlToArcUrl(const storage::FileSystemURL& url);
+
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_CONTENT_FILE_SYSTEM_URL_UTIL_H_