Disable package selection for multiple-selection file dialogs.

ui/shell_dialogs/select_file_dialog_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/shell_dialogs/select_file_dialog.h"
 
 #import <Cocoa/Cocoa.h>
 #include <CoreServices/CoreServices.h>
 
 #include <map>
@@ skipping 143 matching lines @@
     if (is_multi) {
       listener_->MultiFilesSelected(files, params);
     } else {
       listener_->FileSelected(files[0], index, params);
     }
   }
 }
 
 bool SelectFileDialogImpl::ShouldEnableFilename(NSSavePanel* dialog,
                                                 NSString* filename) {
-  // If this is a single open file dialog, disable selecting packages.
-  if (type_map_[dialog] != SELECT_OPEN_FILE)
+  // If this is a single/multiple open file dialog, disable selecting packages.
+  if (type_map_[dialog] != SELECT_OPEN_FILE &&
+      type_map_[dialog] != SELECT_OPEN_MULTI_FILE)
     return true;
 
   return ![[NSWorkspace sharedWorkspace] isFilePackageAtPath:filename];
 }
 
 void SelectFileDialogImpl::SelectFileImpl(
     Type type,
     const base::string16& title,
     const base::FilePath& default_path,
     const FileTypeInfo* file_types,
@@ skipping 242 matching lines @@
   bool isMulti = type == ui::SelectFileDialog::SELECT_OPEN_MULTI_FILE;
   selectFileDialogImpl_->FileWasSelected(panel,
                                          parentWindow,
                                          did_cancel,
                                          isMulti,
                                          paths,
                                          index);
   [panel release];
 }
 
 - (BOOL)panel:(id)sender shouldShowFilename:(NSString *)filename {

[erikchen, 2014/09/29 19:42:59]

For reference, this method was deprecated in 10.6 and got replaced by
panel:shouldEnableURL:. We should eventually make the switch.

[Avi (use Gerrit), 2014/09/29 20:20:39]

Done.

   return selectFileDialogImpl_->ShouldEnableFilename(sender, filename);
 }
 
 @end
 
 namespace ui {
 
 SelectFileDialog* CreateMacSelectFileDialog(
     SelectFileDialog::Listener* listener,
     SelectFilePolicy* policy) {
   return new SelectFileDialogImpl(listener, policy);
 }
 
 }  // namespace ui