[WebMIDI] Remove not needed CancelPermission IPC message.

content/renderer/media/midi_dispatcher.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/midi_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "content/common/media/midi_messages.h"
 #include "third_party/WebKit/public/platform/WebString.h"
@@ skipping 28 matching lines @@
   WebSecurityOrigin security_origin = request.securityOrigin();
   GURL url(security_origin.toString());
   Send(new MidiHostMsg_RequestSysExPermission(routing_id(), bridge_id, url,
       blink::WebUserGestureIndicator::isProcessingUserGesture()));
 }
 
 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;
   }
 }
 
 void MidiDispatcher::OnSysExPermissionApproved(int bridge_id,
                                                bool is_allowed) {
   // |request| can be NULL when the request is canceled.
   WebMIDIPermissionRequest* request = requests_.Lookup(bridge_id);
   if (!request)
     return;
   request->setIsAllowed(is_allowed);
   requests_.Remove(bridge_id);
 }
 
 }  // namespace content