Revert changes to DownloadPrefs regarding PDF auto open.

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 df21f0a0a0432556243302f0daac556de0fac17e..d0c8cfaa6a0abaf5a0643b9418285b817ebb27ad 100644
--- a/chrome/browser/download/download_prefs.h
+++ b/chrome/browser/download/download_prefs.h
@@ -8,7 +8,6 @@
 #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"
@@ -87,12 +86,8 @@ class DownloadPrefs {
   // Return whether the user prefers to open PDF downloads in the platform's
   // default reader.
   bool ShouldOpenPdfInSystemReader() const;
-
-  // Used by tests to disable version checks for Adobe.
-  void DisableAdobeVersionCheckForTests();
 #endif
 
-
   void ResetAutoOpen();
 
  private:
@@ -116,7 +111,6 @@ class DownloadPrefs {
 
 #if defined(OS_WIN) || defined(OS_LINUX) || defined(OS_MACOSX)
   bool should_open_pdf_in_system_reader_;
-  bool disable_adobe_version_check_for_tests_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(DownloadPrefs);