Enable "Hide Extension" option when "Save Link As" on the Mac

content/browser/download/base_file_mac.cc

Index: content/browser/download/base_file_mac.cc
diff --git a/content/browser/download/base_file_mac.cc b/content/browser/download/base_file_mac.cc
index f3edf12d0948c6360d306c17571e62c97b392bbe..9a756c38f02d6da0b9c0cab417e4f6821d046ad8 100644
--- a/content/browser/download/base_file_mac.cc
+++ b/content/browser/download/base_file_mac.cc
@@ -15,6 +15,13 @@ DownloadInterruptReason BaseFile::AnnotateWithSourceInformation() {
 
   AddQuarantineMetadataToFile(full_path_, source_url_, referrer_url_);
   AddOriginMetadataToFile(full_path_, source_url_, referrer_url_);
+
+  // Hide the downloaded file's extension in the Finder if the user chose that
+  // option in the save panel.
+  if (hide_file_extension_) {
+    SetExtensionHiddenForFile(full_path_, true);
+  }
+
   return DOWNLOAD_INTERRUPT_REASON_NONE;
 }