Migrate callbacks in video decode stats reporter.

In the following call chain, a periodic timer invokes the callback,
therefore, it must be a repeating callback:
* https://cs.chromium.org/chromium/src/media/blink/video_decode_stats_reporter.cc?rcl=26a281f509fa5217972a45cae8fff0a32e5a1f44&l=289
* https://cs.chromium.org/chromium/src/media/blink/video_decode_stats_reporter.cc?rcl=26a281f509fa5217972a45cae8fff0a32e5a1f44&l=286
* https://cs.chromium.org/chromium/src/media/blink/video_decode_stats_reporter.cc?rcl=26a281f509fa5217972a45cae8fff0a32e5a1f44&l=126

This is part of the base::Callback migration.

Context: https://cs.chromium.org/chromium/src/docs/callback.md?rcl=9fcc3764aea8f97e9f6de4a9ee61d554e67edcda&l=40

Bug: 714018
Change-Id: I234f6bdf2144e9b25665356873f606693563c996
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2035956Reviewed-by: danakj <danakj@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Jose Lopes <jabolopes@google.com>
Cr-Commit-Position: refs/heads/master@{#742574}

media/blink/video_decode_stats_reporter.h

@@ -32,7 +32,7 @@ namespace media {
 // finalized at destruction and process tear-down.
 class MEDIA_BLINK_EXPORT VideoDecodeStatsReporter {
  public:
-  using GetPipelineStatsCB = base::Callback<PipelineStatistics(void)>;
+  using GetPipelineStatsCB = base::RepeatingCallback<PipelineStatistics(void)>;
 
   VideoDecodeStatsReporter(
       mojo::PendingRemote<mojom::VideoDecodeStatsRecorder> recorder_remote,

media/blink/video_decode_stats_reporter_unittest.cc

@@ -189,8 +189,8 @@ class VideoDecodeStatsReporterTest : public ::testing::Test {
       const base::Optional<CdmConfig> cdm_config = kDefaultCdmConfig) {
     reporter_ = std::make_unique<VideoDecodeStatsReporter>(
         SetupRecordInterceptor(&interceptor_),
-        base::Bind(&VideoDecodeStatsReporterTest::GetPipelineStatsCB,
-                   base::Unretained(this)),
+        base::BindRepeating(&VideoDecodeStatsReporterTest::GetPipelineStatsCB,
+                            base::Unretained(this)),
         profile, natural_size, key_system, cdm_config, task_runner_,
         task_runner_->GetMockTickClock());
   }

media/blink/webmediaplayer_impl.cc

@@ -1993,8 +1993,8 @@ void WebMediaPlayerImpl::CreateVideoDecodeStatsReporter() {
   // Create capabilities reporter and synchronize its initial state.
   video_decode_stats_reporter_.reset(new VideoDecodeStatsReporter(
       std::move(recorder),
-      base::Bind(&WebMediaPlayerImpl::GetPipelineStatistics,
-                 base::Unretained(this)),
+      base::BindRepeating(&WebMediaPlayerImpl::GetPipelineStatistics,
+                          base::Unretained(this)),
       pipeline_metadata_.video_decoder_config.profile(),
       pipeline_metadata_.natural_size, key_system_, cdm_config_,
       frame_->GetTaskRunner(blink::TaskType::kInternalMedia)));