[Mac] Use an AppleEvent to tell the Finder to open downloaded items, rather than NSWorkspace.

BUG=32921,50263
TEST=Force a PDF to download. Quit Preview, if open. Open the downloaded PDF from the download shelf. Preview opens and becomes frontmost.
TEST=Download a file of a type that you do not have an application with which to open it. Open it from the download shelf. Finder bounces for your attention to choose an application to open it.

Review URL: http://codereview.chromium.org/3151011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@56026 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/base.gypi b/base/base.gypi
index 62b3de3..a3078200 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -184,6 +184,7 @@
           'resource_util.h',
           'safe_strerror_posix.cc',
           'safe_strerror_posix.h',
+          'scoped_aedesc.h',
           'scoped_bstr_win.cc',
           'scoped_bstr_win.h',
           'scoped_callback_factory.h',
@@ -331,6 +332,11 @@
               ],
             },
           ],
+          [ 'OS != "mac"', {
+              'sources!': [
+                'scoped_aedesc.h'
+              ],
+          }],
           # For now, just test the *BSD platforms enough to exclude them.
           # Subsequent changes will include them further.
           [ 'OS != "freebsd"', {