Adding a DownloadRestrictions group policy.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 7b2eb7feadbad92905f848d76dc267dbf2dab787..38e27d95ae783b67cd40449a6b2ae387b77f4299 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -72,6 +72,13 @@ const char kDefaultApps[] = "default_apps";
 // handling code reads local state, while extension APIs use profile pref.
 const char kDisableScreenshots[] = "disable_screenshots";
 
+// Prevents certain types of downloads based on integre value:
+// 0 - Allow all downloads (default)
+// 1 - Disable Safe Browsing dangerous files
+// 2 - Disable Safe Browsing potentially dangerous files
+// 3 - Disable all downloads
+const char kDownloadRestrictions[] = "download_restrictions";
+
 // If set to true profiles are created in ephemeral mode and do not store their
 // data in the profile folder on disk but only in memory.
 const char kForceEphemeralProfiles[] = "profile.ephemeral_mode";