Fix bug: MIDI causes crash on onContentSettingChanged()

chrome/browser/permissions/permission_manager_unittest.cc

 // Copyright 2015 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 "chrome/browser/permissions/permission_manager.h"
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/permissions/permission_manager_factory.h"
@@ skipping 283 matching lines @@
 
   GetHostContentSettingsMap()->SetContentSettingDefaultScope(
       url(), url(), CONTENT_SETTINGS_TYPE_GEOLOCATION, std::string(),
       CONTENT_SETTING_ASK);
 
   EXPECT_TRUE(callback_called());
   EXPECT_EQ(PermissionStatus::ASK, callback_result());
 
   GetPermissionManager()->UnsubscribePermissionStatusChange(subscription_id);
 }
+
+TEST_F(PermissionManagerTest, SubscribeMIDIPermission) {
+  int subscription_id = GetPermissionManager()->SubscribePermissionStatusChange(
+      PermissionType::MIDI, url(), url(),
+      base::Bind(&PermissionManagerTest::OnPermissionChange,
+                 base::Unretained(this)));
+
+  CheckPermissionStatus(PermissionType::GEOLOCATION, PermissionStatus::ASK);
+  GetHostContentSettingsMap()->SetContentSettingDefaultScope(
+      url(), url(), CONTENT_SETTINGS_TYPE_GEOLOCATION, std::string(),
+      CONTENT_SETTING_ALLOW);
+  CheckPermissionStatus(PermissionType::GEOLOCATION, PermissionStatus::GRANTED);
+
+  EXPECT_FALSE(callback_called());
+
+  GetPermissionManager()->UnsubscribePermissionStatusChange(subscription_id);
+}