Stop passing "force" option when invoking cros-disks's Unmount method.

chromeos/dbus/cros_disks_client.cc

Index: chromeos/dbus/cros_disks_client.cc
diff --git a/chromeos/dbus/cros_disks_client.cc b/chromeos/dbus/cros_disks_client.cc
index 47f961d3cca084115b00520d142c4fbc5b7b755c..42ed90ee9c1b88f776e0d1640c315df18ca9d9e6 100644
--- a/chromeos/dbus/cros_disks_client.cc
+++ b/chromeos/dbus/cros_disks_client.cc
@@ -40,10 +40,6 @@ const char kReadWriteOption[] = "rw";
 const char kRemountOption[] = "remount";
 const char kMountLabelOption[] = "mountlabel";
 
-const char* kDefaultUnmountOptions[] = {
-  "force",
-};
-
 const char kLazyUnmountOption[] = "lazy";
 
 // Checks if retrieved media type is in boundaries of DeviceMediaType.
@@ -133,9 +129,7 @@ class CrosDisksClientImpl : public CrosDisksClient {
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(device_path);
 
-    std::vector<std::string> unmount_options(
-        kDefaultUnmountOptions,
-        kDefaultUnmountOptions + arraysize(kDefaultUnmountOptions));
+    std::vector<std::string> unmount_options;
     if (options == UNMOUNT_OPTIONS_LAZY)
       unmount_options.push_back(kLazyUnmountOption);