Remove .dmg from the list of dangerous file extensions for Mac OS X.

chrome/browser/download/download_extensions.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 <set>
 #include <string>
 
 #include "chrome/browser/download/download_extensions.h"
 
 #include "base/string_util.h"
@@ skipping 158 matching lines @@
   { "vsmacros", AllowOnUserGesture },
   { "vss", AllowOnUserGesture },
   { "vst", AllowOnUserGesture },
   { "vsw", AllowOnUserGesture },
   { "ws", AllowOnUserGesture },
   { "wsc", AllowOnUserGesture },
   { "wsf", AllowOnUserGesture },
   { "wsh", AllowOnUserGesture },
   { "xbap", Dangerous },
 #elif defined(OS_MACOSX)
-  // TODO(thakis): Figure out what makes sense here -- crbug.com/19096
-  { "app", AllowOnUserGesture },
-  { "dmg", AllowOnUserGesture },
+  { "bash", AllowOnUserGesture },
+  { "command", AllowOnUserGesture },
+  { "csh", AllowOnUserGesture },
+  { "ksh", AllowOnUserGesture },
+  { "pkg", AllowOnUserGesture },
+  { "sh", AllowOnUserGesture },
+  { "shar", AllowOnUserGesture },
+  { "tcsh", AllowOnUserGesture },
 #elif defined(OS_POSIX)
   // TODO(estade): lengthen this list.
   { "bash", AllowOnUserGesture },
   { "csh", AllowOnUserGesture },
   { "deb", AllowOnUserGesture },
   { "exe", AllowOnUserGesture },
   { "ksh", AllowOnUserGesture },
   { "rpm", AllowOnUserGesture },
   { "sh", AllowOnUserGesture },
+  { "shar", AllowOnUserGesture },
   { "tcsh", AllowOnUserGesture },
 #endif
 };
 
 DownloadDangerLevel GetFileDangerLevel(const FilePath& path) {
   FilePath::StringType extension(path.Extension());
   if (extension.empty())
     return NotDangerous;
   if (!IsStringASCII(extension))
     return NotDangerous;
@@ skipping 42 matching lines @@
   for (size_t i = 0; i < arraysize(kExecutableBlackList); ++i) {
     if (net::MatchesMimeType(kExecutableBlackList[i], mime_type))
       return false;
   }
   // We consider only other application types to be executable.
   return net::MatchesMimeType("application/*", mime_type);
 }
 
 
 }  // namespace download_util