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

chrome/browser/download/download_prefs.cc

Index: chrome/browser/download/download_prefs.cc
diff --git a/chrome/browser/download/download_prefs.cc b/chrome/browser/download/download_prefs.cc
index 5dba83ae35e03aaa002ef80cbee6acf16e333039..8acc6cf10fbc4da0502bb6197b6ef47f28f3c112 100644
--- a/chrome/browser/download/download_prefs.cc
+++ b/chrome/browser/download/download_prefs.cc
@@ -134,6 +134,9 @@ DownloadPrefs::DownloadPrefs(Profile* profile) : profile_(profile) {
 #if defined(OS_WIN)
   should_open_pdf_in_adobe_reader_ =
       prefs->GetBoolean(prefs::kOpenPdfDownloadInAdobeReader);
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+  should_open_pdf_in_system_reader_ =
+      prefs->GetBoolean(prefs::kOpenPdfDownloadInSystemReader);
 #endif
 
   // If the download path is dangerous we forcefully reset it. But if we do
@@ -209,6 +212,11 @@ void DownloadPrefs::RegisterProfilePrefs(
       prefs::kOpenPdfDownloadInAdobeReader,
       false,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+  registry->RegisterBooleanPref(
+      prefs::kOpenPdfDownloadInSystemReader,
+      false,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 #endif
 }
 
@@ -287,6 +295,9 @@ bool DownloadPrefs::IsAutoOpenUsed() const {
 #if defined(OS_WIN)
   if (ShouldOpenPdfInAdobeReader())
     return true;
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+  if (ShouldOpenPdfInSystemReader())
+    return true;
 #endif
   return !auto_open_.empty();
 }
@@ -303,6 +314,9 @@ bool DownloadPrefs::IsAutoOpenEnabledBasedOnExtension(
       DownloadTargetDeterminer::IsAdobeReaderUpToDate() &&
       ShouldOpenPdfInAdobeReader())
     return true;
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+  if (extension == FILE_PATH_LITERAL("pdf") && ShouldOpenPdfInSystemReader())
+    return true;
 #endif
   return auto_open_.find(extension) != auto_open_.end();
 }
@@ -343,11 +357,25 @@ void DownloadPrefs::SetShouldOpenPdfInAdobeReader(bool should_open) {
 bool DownloadPrefs::ShouldOpenPdfInAdobeReader() const {
   return should_open_pdf_in_adobe_reader_;
 }
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+void DownloadPrefs::SetShouldOpenPdfInSystemReader(bool should_open) {
+  if (should_open_pdf_in_system_reader_ == should_open)
+    return;
+  should_open_pdf_in_system_reader_ = should_open;
+  profile_->GetPrefs()->SetBoolean(prefs::kOpenPdfDownloadInSystemReader,
+                                   should_open);
+}
+
+bool DownloadPrefs::ShouldOpenPdfInSystemReader() const {
+  return should_open_pdf_in_system_reader_;
+}
 #endif
 
 void DownloadPrefs::ResetAutoOpen() {
 #if defined(OS_WIN)
   SetShouldOpenPdfInAdobeReader(false);
+#elif defined(OS_MACOSX) || defined(OS_LINUX)
+  SetShouldOpenPdfInSystemReader(false);
 #endif
   auto_open_.clear();
   SaveAutoOpenState();