Update the error message in the Files app via Downloads panel.

chrome/browser/chromeos/file_manager/open_util.cc

 // 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 "chrome/browser/chromeos/file_manager/open_util.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 124 matching lines @@
       profile,
       path,
       base::Bind(&OpenFileWithMimeType, profile, path, url, callback));
 }
 
 // Called when execution of ContinueOpenItem() is completed.
 void OnContinueOpenItemCompleted(Profile* profile,
                                  const base::FilePath& file_path,
                                  bool result) {
   if (!result) {
-    ShowWarningMessageBox(
-        profile, file_path, IDS_FILE_BROWSER_ERROR_VIEWING_FILE);
+    int message;
+    if (file_path.Extension() == FILE_PATH_LITERAL(".dmg"))
+      message = IDS_FILE_BROWSER_ERROR_VIEWING_FILE_FOR_DMG;
+    else if (file_path.Extension() == FILE_PATH_LITERAL(".exe") ||
+             file_path.Extension() == FILE_PATH_LITERAL(".msi"))
+      message = IDS_FILE_BROWSER_ERROR_VIEWING_FILE_FOR_EXECUTABLE;
+    else
+      message = IDS_FILE_BROWSER_ERROR_VIEWING_FILE;
+    ShowWarningMessageBox(profile, file_path, message);
   }
 }
 
 // Used to implement OpenItem().
 void ContinueOpenItem(Profile* profile,
                       const base::FilePath& file_path,
                       const GURL& url,
                       base::File::Error error) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
@@ skipping 67 matching lines @@
   GURL url;
   if (!ConvertPath(profile, file_path, &converted_path, &url))
     return;
 
   // This action changes the selection so we do not reuse existing tabs.
   OpenFileManagerWithInternalActionId(profile, url, "select");
 }
 
 }  // namespace util
 }  // namespace file_manager