Add option to open PDFs in system viewer to OS X and Linux.

chrome/browser/download/chrome_download_manager_delegate.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/download/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 701 matching lines @@
 bool ChromeDownloadManagerDelegate::IsOpenInBrowserPreferreredForFile(
     const base::FilePath& path) {
   // On Windows, PDFs should open in Acrobat Reader if the user chooses.
 #if defined(OS_WIN)
   if (path.MatchesExtension(FILE_PATH_LITERAL(".pdf")) &&
       DownloadTargetDeterminer::IsAdobeReaderUpToDate()) {
     return !download_prefs_->ShouldOpenPdfInAdobeReader();
   }
 #endif
 
+#if defined(OS_MACOSX) || defined(OS_LINUX)

[Lei Zhang, 2014/10/21 11:07:06]

I'm not 100% sure what pieces of code Chrome for iOS uses, but just to note,
OS_MACOSX is true for iOS.

[palmer, 2014/10/21 20:31:49]

OK, checking for defined(OS_MACOSX) && !defined(OS_IOS).

+  if (path.MatchesExtension(FILE_PATH_LITERAL(".pdf"))) {
+    return !download_prefs_->ShouldOpenPdfInSystemReader();
+  }
+#endif
+
   // On Android, always prefer opening with an external app. On ChromeOS, there
   // are no external apps so just allow all opens to be handled by the "System."
 #if !defined(OS_ANDROID) && !defined(OS_CHROMEOS) && defined(ENABLE_PLUGINS)
   // TODO(asanka): Consider other file types and MIME types.
   // http://crbug.com/323561
   if (path.MatchesExtension(FILE_PATH_LITERAL(".pdf")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".htm")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".html")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".shtm")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".shtml")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".svg")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xht")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtm")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtml")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xsl")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xslt"))) {
     return true;
   }
 #endif
   return false;
 }