register extension handler for every session created

lib/browser/api/session.js

@@ -10,7 +10,9 @@ const fromPartition = function (partition, persist) {
     throw new Error('session module can only be used when app is ready')
   }
 
-  return bindings.fromPartition(partition, persist)
+  let session = bindings.fromPartition(partition, persist)
+  process.emit('session-created', session)
+  return session
 }
 
 // Returns the Session from |partition| string.

lib/browser/chrome-extension.js

@@ -280,10 +280,12 @@ app.once('ready', function () {
       }
     })
   }
-  protocol.registerBufferProtocol('chrome-extension', chromeExtensionHandler, function (error) {
-    if (error) {
-      console.error(`Unable to register chrome-extension protocol: ${error}`)
-    }
+  process.on('session-created', function (session) {
+    session.protocol.registerBufferProtocol('chrome-extension', chromeExtensionHandler, function (error) {
+      if (error) {
+        console.error(`Unable to register chrome-extension protocol: ${error}`)
+      }
+    })
   })
 
   // Load persisted extensions.