Remove bogus DCHECK in content::UserMediaClientImpl and update unit test

content/renderer/media/user_media_client_impl_unittest.cc

 // Copyright (c) 2012 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/user_media_client_impl.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 246 matching lines @@
   void FakeMediaStreamDispatcherRequestUserMediaComplete() {
     // Audio request ID is used as the shared request ID.
     used_media_impl_->OnStreamGenerated(
         ms_dispatcher_->audio_input_request_id(),
         ms_dispatcher_->stream_label(),
         ms_dispatcher_->audio_input_array(),
         ms_dispatcher_->video_array());
   }
 
   void FakeMediaStreamDispatcherRequestMediaDevicesComplete() {
+    // There may be repeated replies due to device or configuration changes.
     used_media_impl_->OnDevicesEnumerated(
         ms_dispatcher_->audio_input_request_id(),
         ms_dispatcher_->audio_input_array());
+    used_media_impl_->OnDevicesEnumerated(
+        ms_dispatcher_->audio_input_request_id(),
+        ms_dispatcher_->audio_input_array());
     used_media_impl_->OnDevicesEnumerated(
         ms_dispatcher_->audio_output_request_id(),
         ms_dispatcher_->audio_output_array());
     used_media_impl_->OnDevicesEnumerated(
+        ms_dispatcher_->audio_output_request_id(),
+        ms_dispatcher_->audio_output_array());
+    used_media_impl_->OnDevicesEnumerated(
         ms_dispatcher_->video_request_id(),
         ms_dispatcher_->video_array());
+    used_media_impl_->OnDevicesEnumerated(
+        ms_dispatcher_->video_request_id(),
+        ms_dispatcher_->video_array());
   }
 
   void FakeMediaStreamDispatcherRequestSourcesComplete() {
     used_media_impl_->OnDevicesEnumerated(
         ms_dispatcher_->audio_input_request_id(),
         ms_dispatcher_->audio_input_array());
     used_media_impl_->OnDevicesEnumerated(
         ms_dispatcher_->video_request_id(),
         ms_dispatcher_->video_array());
   }
@@ skipping 418 matching lines @@
   // Now we close the web frame, if in the above Stop() call,
   // UserMediaClientImpl accidentally removed audio track, then video track will
   // be removed again here, which is incorrect.
   used_media_impl_->FrameWillClose();
   blink::WebHeap::collectAllGarbageForTesting();
   EXPECT_EQ(1, ms_dispatcher_->stop_video_device_counter());
   EXPECT_EQ(1, ms_dispatcher_->stop_audio_device_counter());
 }
 
 }  // namespace content