Implement DeleteFile and DeleteDirectory.

chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm

Index: chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm
diff --git a/chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm b/chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm
index a8781bcceca3c99335739b8d02e490f862c8860e..a0f48abe8f45f028e372b79bd9e6c1abcee07298 100644
--- a/chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm
+++ b/chrome/browser/media_galleries/mac/mtp_device_delegate_impl_mac.mm
@@ -209,7 +209,7 @@ void MTPDeviceDelegateImplMac::ReadBytes(
   NOTREACHED();
 }
 
-bool MTPDeviceDelegateImplMac::IsReadOnly() {
+bool MTPDeviceDelegateImplMac::IsReadOnly() const {
   return true;
 }
 
@@ -221,6 +221,20 @@ void MTPDeviceDelegateImplMac::CopyFileFromLocal(
   NOTREACHED();
 }
 
+void MTPDeviceDelegateImplMac::DeleteFile(
+    const base::FilePath& file_path,
+    const DeleteFileSuccessCallback& success_callback,
+    const ErrorCallback& error_callback) {
+  NOTREACHED();
+}
+
+void MTPDeviceDelegateImplMac::DeleteDirectory(
+    const base::FilePath& file_path,
+    const DeleteDirectorySuccessCallback& success_callback,
+    const ErrorCallback& error_callback) {
+  NOTREACHED();
+}
+
 void MTPDeviceDelegateImplMac::CancelPendingTasksAndDeleteDelegate() {
   content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
       base::Bind(&MTPDeviceDelegateImplMac::CancelAndDelete,