Minor refactoring of SelectSettings results for consistency.

content/renderer/media/media_stream_constraints_util_video_content.h

 // Copyright 2017 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.
 
 #ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_CONSTRAINTS_UTIL_VIDEO_CONTENT_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_CONSTRAINTS_UTIL_VIDEO_CONTENT_H_
 
 #include <string>
 
+#include "base/logging.h"
 #include "content/common/content_export.h"
 #include "media/capture/video_capture_types.h"
 #include "third_party/webrtc/base/optional.h"
 
 namespace blink {
 class WebMediaConstraints;
 }
 
 namespace content {
 
@@ skipping 19 matching lines @@
   VideoContentCaptureSourceSelectionResult(
       VideoContentCaptureSourceSelectionResult&& other);
   VideoContentCaptureSourceSelectionResult& operator=(
       VideoContentCaptureSourceSelectionResult&& other);
   ~VideoContentCaptureSourceSelectionResult();
 
   bool HasValue() const { return failed_constraint_name_ == nullptr; }
 
   // Accessors.
   const char* failed_constraint_name() const { return failed_constraint_name_; }
-  const std::string& device_id() const { return device_id_; }
+  const std::string& device_id() const {
+    DCHECK(HasValue());
+    return device_id_;
+  }
   const rtc::Optional<bool>& noise_reduction() const {
+    DCHECK(HasValue());
     return noise_reduction_;
   }
-  media::VideoCaptureParams capture_params() const { return capture_params_; }
+  media::VideoCaptureParams capture_params() const {
+    DCHECK(HasValue());
+    return capture_params_;
+  }
 
   // Convenience accessors for fields embedded in the |capture_params_| field.
   int Height() const;
   int Width() const;
   float FrameRate() const;
   media::ResolutionChangePolicy ResolutionChangePolicy() const;
 
  private:
   const char* failed_constraint_name_;
   std::string device_id_;
   rtc::Optional<bool> noise_reduction_;
   media::VideoCaptureParams capture_params_;
 };
 
 // This function performs source and source-settings selection for content
 // video capture based on the given |constraints|.
 VideoContentCaptureSourceSelectionResult CONTENT_EXPORT
 SelectVideoContentCaptureSourceSettings(
     const blink::WebMediaConstraints& constraints);
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_CONSTRAINTS_UTIL_VIDEO_CONTENT_H_