Handle the case where IAttachmentExecute::Save() deletes a downloaded file.

content/browser/download/base_file.cc

Index: content/browser/download/base_file.cc
diff --git a/content/browser/download/base_file.cc b/content/browser/download/base_file.cc
index 65fd7a1991ef5d3ce585985e3b5d33c8656a3c65..e63174b5e66029eb4af715e08c3d066fe8eeb084 100644
--- a/content/browser/download/base_file.cc
+++ b/content/browser/download/base_file.cc
@@ -217,7 +217,8 @@ void BaseFile::Finish() {
 
 // OS_WIN, OS_MACOSX and OS_LINUX have specialized implementations.
 #if !defined(OS_WIN) && !defined(OS_MACOSX) && !defined(OS_LINUX)
-void BaseFile::AnnotateWithSourceInformation() {
+content::DownloadInterruptReason BaseFile::AnnotateWithSourceInformation() {
+  return content::DOWNLOAD_INTERRUPT_REASON_NONE;
 }
 #endif