Add a whitelist for the new binary download protection.

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 8d2cc971e9cbfa94339d9197cd915d9821513f59..a8393f8cb63b27e8978f3df5fc9f69bc46284a9a 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -227,6 +227,10 @@ const char kAutologinEnabled[] = "autologin.enabled";
 // Boolean that is true when SafeBrowsing is enabled.
 const char kSafeBrowsingEnabled[] = "safebrowsing.enabled";
 
+// Boolean that is true when SafeBrowsing opt-in download protection is enabled.
+const char kSafeBrowsingOptinDownloadProtectionEnabled[] =
+    "safebrowsing.optin_download_protection";
+
 // Boolean that is true when SafeBrowsing Malware Report is enabled.
 const char kSafeBrowsingReportingEnabled[] =
     "safebrowsing.reporting_enabled";