Add a data source field for volumes.

chrome/browser/chromeos/file_system_provider/provided_file_system_info.h

Index: chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
diff --git a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
index 795577ce3c72814c833b8f8daa8acfe030b7ade1..53a610f8a4fc8201fa5a1c604e195097c4f9a2b5 100644
--- a/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
+++ b/chrome/browser/chromeos/file_system_provider/provided_file_system_info.h
@@ -12,6 +12,9 @@
 namespace chromeos {
 namespace file_system_provider {
 
+// Source of the file system's contents.
+enum Source { SOURCE_UNKNOWN, SOURCE_FILE, SOURCE_DEVICE, SOURCE_NETWORK };
+
 // Options for creating the provided file system info.
 struct MountOptions {
   MountOptions();
@@ -23,6 +26,7 @@ struct MountOptions {
   std::string file_system_id;
   std::string display_name;
   bool writable;
+  Source source;
   bool supports_notify_tag;
   int opened_files_limit;
 };
@@ -42,6 +46,7 @@ class ProvidedFileSystemInfo {
   const std::string& file_system_id() const { return file_system_id_; }
   const std::string& display_name() const { return display_name_; }
   bool writable() const { return writable_; }
+  Source source() const { return source_; }
   bool supports_notify_tag() const { return supports_notify_tag_; }
   int opened_files_limit() const { return opened_files_limit_; }
   const base::FilePath& mount_path() const { return mount_path_; }
@@ -59,6 +64,9 @@ class ProvidedFileSystemInfo {
   // Whether the file system is writable or just read-only.
   bool writable_;
 
+  // Source of the file system's contents. By default SOURCE_UNKNOWN.
+  Source source_;
+
   // Supports tags for file/directory change notifications.
   bool supports_notify_tag_;