Move media/capture/content/feedback_signal_accumulator{.h,_unittest.cc} to media/base

media/base/feedback_signal_accumulator.h

 // Copyright (c) 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.
 
-#ifndef MEDIA_CAPTURE_CONTENT_FEEDBACK_SIGNAL_ACCUMULATOR_H_
-#define MEDIA_CAPTURE_CONTENT_FEEDBACK_SIGNAL_ACCUMULATOR_H_
+#ifndef MEDIA_BASE_FEEDBACK_SIGNAL_ACCUMULATOR_H_
+#define MEDIA_BASE_FEEDBACK_SIGNAL_ACCUMULATOR_H_
 
 #include "base/time/time.h"
-#include "media/capture/capture_export.h"
 
 namespace media {
 
 // Utility class for maintaining an exponentially-decaying average of feedback
 // signal values whose updates occur at undetermined, possibly irregular time
 // intervals.
 //
 // Feedback signals can be made by multiple sources.  Meaning, there can be
 // several values provided for the same timestamp.  In this case, the greatest
 // value is retained and used to re-compute the average.  Therefore, the values
@@ skipping 79 matching lines @@
   TimeType reset_time_;   // |timestamp| passed in last call to Reset().
   double average_;        // Current accumulated average.
   double update_value_;   // Latest |value| accepted by Update().
   TimeType update_time_;  // Latest |timestamp| accepted by Update().
   double prior_average_;  // Accumulated average before last call to Update().
   TimeType prior_update_time_;  // |timestamp| in prior call to Update().
 };
 
 }  // namespace media
 
-#endif  // MEDIA_CAPTURE_CONTENT_FEEDBACK_SIGNAL_ACCUMULATOR_H_
+#endif  // MEDIA_BASE_FEEDBACK_SIGNAL_ACCUMULATOR_H_