Adds a pref and a policy to decide if PDFs should always be opened externally.

chrome/browser/download/download_prefs.h

Index: chrome/browser/download/download_prefs.h
diff --git a/chrome/browser/download/download_prefs.h b/chrome/browser/download/download_prefs.h
index 01bd1c9d5ec2e70b849a01f937b87a6424738eef..0a1c641e6f70e46849dca1653fa2e47e1f0631ed 100644
--- a/chrome/browser/download/download_prefs.h
+++ b/chrome/browser/download/download_prefs.h
@@ -8,6 +8,7 @@
 #include <set>
 
 #include "base/files/file_path.h"
+#include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "components/prefs/pref_member.h"
@@ -94,6 +95,11 @@ class DownloadPrefs {
  private:
   void SaveAutoOpenState();
 
+#if defined(OS_WIN) || defined(OS_LINUX) || defined(OS_MACOSX)
+  // Used by tests to switch off version checks for Adobe.

[Bernhard Bauer, 2016/09/29 08:44:35]

Rename the method so it states that the checks are disabled?

[pastarmovj, 2016/09/29 12:14:41]

Done.

+  void OverrideAdobeVersionCheckForTests();
+#endif
+
   Profile* profile_;
 
   BooleanPrefMember prompt_for_download_;
@@ -112,6 +118,9 @@ class DownloadPrefs {
 
 #if defined(OS_WIN) || defined(OS_LINUX) || defined(OS_MACOSX)
   bool should_open_pdf_in_system_reader_;
+  bool override_adobe_version_check_for_tests_;
+
+  FRIEND_TEST_ALL_PREFIXES(DownloadPrefsTest, AlwaysOpenPdfExternally);

[Bernhard Bauer, 2016/09/29 08:44:35]

Friend declarations go first in the private section. Alternatively, just make
the method public? It has a ...ForTests suffix anyway, which I think should be
good enough to deter people from using it in production code.

[pastarmovj, 2016/09/29 12:14:41]

Done.

 #endif
 
   DISALLOW_COPY_AND_ASSIGN(DownloadPrefs);