[Mojo Video Capture] Use string keys instead of VideoCaptureDeviceDescriptor

services/video_capture/fake_device_test.cc

 // Copyright 2016 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 "services/video_capture/fake_device_test.h"
 
 #include "base/run_loop.h"
 
 using testing::_;
 using testing::Invoke;
@@ skipping 15 matching lines @@
 
   // Query factory for supported formats of fake device
   base::RunLoop wait_loop;
   EXPECT_CALL(supported_formats_receiver_, OnGetSupportedFormatsCallback(_))
       .WillOnce(Invoke(
           [this, &wait_loop](const std::vector<VideoCaptureFormat>& formats) {
             fake_device_first_supported_format_ = formats[0];
             wait_loop.Quit();
           }));
   factory_->GetSupportedFormats(
-      fake_device_descriptor_,
+      fake_device_descriptor_.device_id,
       base::Bind(&MockSupportedFormatsReceiver::OnGetSupportedFormatsCallback,
       base::Unretained(&supported_formats_receiver_)));
   wait_loop.Run();
 
   requestable_settings_.format = fake_device_first_supported_format_;
   requestable_settings_.resolution_change_policy =
       media::RESOLUTION_POLICY_FIXED_RESOLUTION;
   requestable_settings_.power_line_frequency =
       media::PowerLineFrequency::FREQUENCY_DEFAULT;
 
   factory_->CreateDeviceProxy(
-      std::move(fake_device_descriptor_), mojo::GetProxy(&fake_device_proxy_),
+      std::move(fake_device_descriptor_.device_id),
+      mojo::GetProxy(&fake_device_proxy_),
       base::Bind([](mojom::DeviceAccessResultCode result_code) {
         ASSERT_EQ(mojom::DeviceAccessResultCode::SUCCESS, result_code);
       }));
 }
 
 }  // namespace video_capture