Declare kAppendWholeFile as constexpr

media/test/mock_media_source.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 MEDIA_TEST_MOCK_MEDIA_SOURCE_H_
 #define MEDIA_TEST_MOCK_MEDIA_SOURCE_H_
 
+#include <limits>
+
 #include "base/time/time.h"
 #include "media/base/demuxer.h"
 #include "media/base/pipeline_status.h"
 #include "media/filters/chunk_demuxer.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace media {
 
 // Indicates that the whole file should be appended.
-extern const size_t kAppendWholeFile;
+constexpr size_t kAppendWholeFile = std::numeric_limits<size_t>::max();
 
 // Helper class that emulates calls made on the ChunkDemuxer by the
 // Media Source API.
 class MockMediaSource {
  public:
   MockMediaSource(const std::string& filename,
                   const std::string& mimetype,
                   size_t initial_append_size);
   ~MockMediaSource();
 
@@ skipping 50 matching lines @@
   PipelineStatusCB demuxer_failure_cb_;
   Demuxer::EncryptedMediaInitDataCB encrypted_media_init_data_cb_;
   base::TimeDelta last_timestamp_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(MockMediaSource);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_TEST_MOCK_MEDIA_SOURCE_H_