Bug 1361798 - Configure Nightly to download and use the flash 3rd party blocklist, in preparation for switching Flash as Click-to-Activate. r=bsmedberg

This pref change will means that Flash will also start to be blocked on null or system principals, including chrome-privileged test files (e.g. mochitest-chrome/browser-chrome).

MozReview-Commit-ID: CmxF2dJubwS

browser/app/profile/firefox.js

@@ -683,6 +683,10 @@ pref("plugin.defaultXpi.state", 2);
 pref("plugin.state.flash", 2);
 pref("plugin.state.java", 1);
 
+#ifdef NIGHTLY_BUILD
+pref("plugins.flashBlock.enabled", true);
+#endif
+
 #ifdef XP_WIN
 pref("browser.preferences.instantApply", false);
 #else