[WebMIDI] Remove not needed CancelPermission IPC message.

content/renderer/media/midi_dispatcher.cc

Index: content/renderer/media/midi_dispatcher.cc
diff --git a/content/renderer/media/midi_dispatcher.cc b/content/renderer/media/midi_dispatcher.cc
index 84d10f7fc3e37b3776b1797016d0bb9a36306d30..b281389ee5427719f0a7ce08b9119db570efdd24 100644
--- a/content/renderer/media/midi_dispatcher.cc
+++ b/content/renderer/media/midi_dispatcher.cc
@@ -46,14 +46,10 @@ void MidiDispatcher::cancelSysexPermissionRequest(
     const WebMIDIPermissionRequest& request) {
   for (Requests::iterator it(&requests_); !it.IsAtEnd(); it.Advance()) {
     WebMIDIPermissionRequest* value = it.GetCurrentValue();
-    if (value->equals(request)) {
-      base::string16 origin = request.securityOrigin().toString();
-      Send(new MidiHostMsg_CancelSysExPermissionRequest(
-          routing_id(), it.GetCurrentKey(), GURL(origin)));
-      // The request will be removed by OnSysExPermissionApproved once
-      // the blink MIDIAccessInitializer object is deleted.

[mlamouri (slow - plz ping), 2014/10/09 12:47:36]

That doesn't seem to be true.

[Charlie Reis, 2014/10/09 17:11:31]

Sad that there's no test for this class to catch that.  Feel free to add one if
it's easy, but I won't block this CL for it.

[mlamouri (slow - plz ping), 2014/10/09 21:33:50]

Having the |request| pending would only have it leaked until the renderer is
destroyed. Not a terrible thing. Also, testing that might require a browser test
which is some kind of heavy artillery given the benefits.

-      break;
-    }
+    if (!value->equals(request))
+      continue;
+    requests_.Remove(it.GetCurrentKey());
+    break;
   }
 }