Bug 1278762 - Support general context menu actions in RDM. r=ochameau

MozReview-Commit-ID: 3jjAyed0yhP

--HG--
extra : rebase_source : f01c88942ff26e97f70def4175afdcddcd1072c7

devtools/client/responsive.html/browser/tunnel.js

@@ -406,6 +406,8 @@ MessageManagerTunnel.prototype = {
   ],
 
   OUTER_TO_INNER_MESSAGE_PREFIXES: [
+    // Messages sent from nsContextMenu.js
+    "ContextMenu:",
     // Messages sent from DevTools
     "debug:",
     // Messages sent from findbar.xml
@@ -420,6 +422,8 @@ MessageManagerTunnel.prototype = {
   ],
 
   INNER_TO_OUTER_MESSAGE_PREFIXES: [
+    // Messages sent to nsContextMenu.js
+    "ContextMenu:",
     // Messages sent to DevTools
     "debug:",
     // Messages sent to findbar.xml