Show the eject button only for removabled and file handlers.

chrome/common/extensions/api/file_manager_private.idl

Index: chrome/common/extensions/api/file_manager_private.idl
diff --git a/chrome/common/extensions/api/file_manager_private.idl b/chrome/common/extensions/api/file_manager_private.idl
index 64295c78e416f54aa0095d6a04cb1133076ccfb0..c351582a7a599bc9082c1f4fd5e0a3a0e622b996 100644
--- a/chrome/common/extensions/api/file_manager_private.idl
+++ b/chrome/common/extensions/api/file_manager_private.idl
@@ -174,6 +174,14 @@ enum EntryTagVisibility {
   public
 };
 
+// Source of the volume data.
+enum Source {
+  file,
+  device,
+  network,
+  system
+};
+
 // A file task represents an action that the file manager can perform over the
 // currently selected files. See
 // chrome/browser/chromeos/extensions/file_manager/file_tasks.h for details
@@ -290,6 +298,9 @@ dictionary VolumeMetadata {
   // Extension providing this volume (for provided file systems).
   DOMString? extensionId;
 
+  // Source of the volume's data.
+  Source source;
+
   // Label of the volume (if available).
   DOMString? volumeLabel;
 
@@ -320,6 +331,9 @@ dictionary VolumeMetadata {
   // Flag that specifies whether the volume contains media.
   boolean hasMedia;
 
+  // Flag that specifies whether the volume is configurable.
+  boolean configurable;
+
   // Additional data about mount, for example, that the filesystem is not
   // supported.
   MountCondition? mountCondition;
@@ -518,7 +532,7 @@ dictionary ProvidingExtension {
 
   // Whether supports mounting multiple instances.
   boolean multipleMounts;
-
+ 
   // Source of file systems' data.
   manifestTypes.FileSystemProviderSource source;
 };