Merge M50: "Don't log PipelineStatus when there is no Pipeline..."

When MSE started logging these events we accidentally started
getting them for the Android MediaSource players.  These metrics
should only be recorded for Pipeline based players.

BUG=589717
TEST=Android MediaSourcePlayer doesn't generate UMA.

Review URL: https://codereview.chromium.org/1747453002

Cr-Commit-Position: refs/heads/master@{#378083}
(cherry picked from commit a14620d)

Review URL: https://codereview.chromium.org/1748833002 .

Cr-Commit-Position: refs/branch-heads/2661@{crosswalk-project#6}
Cr-Branched-From: ef6f6ae-refs/heads/master@{#378081}

content/browser/media/media_internals.cc

@@ -281,20 +281,15 @@ class MediaInternals::MediaInternalsUMAHandler {
 
  private:
   struct PipelineInfo {
-    media::PipelineStatus last_pipeline_status;
-    bool has_audio;
-    bool has_video;
-    bool video_dds;
-    bool video_decoder_changed;
+    bool has_pipeline = false;
+    media::PipelineStatus last_pipeline_status = media::PIPELINE_OK;
+    bool has_audio = false;
+    bool has_video = false;
+    bool video_dds = false;
+    bool video_decoder_changed = false;
     std::string audio_codec_name;
     std::string video_codec_name;
     std::string video_decoder;
-    PipelineInfo()
-        : last_pipeline_status(media::PIPELINE_OK),
-          has_audio(false),
-          has_video(false),
-          video_dds(false),
-          video_decoder_changed(false) {}
   };
 
   // Helper function to report PipelineStatus associated with a player to UMA.
@@ -324,6 +319,10 @@ void MediaInternals::MediaInternalsUMAHandler::SavePlayerState(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   PlayerInfoMap& player_info = renderer_info_[render_process_id];
   switch (event.type) {
+    case media::MediaLogEvent::PIPELINE_STATE_CHANGED: {
+      player_info[event.id].has_pipeline = true;
+      break;
+    }
     case media::MediaLogEvent::PIPELINE_ERROR: {
       int status;
       event.params.GetInteger("pipeline_error", &status);
@@ -404,6 +403,12 @@ std::string MediaInternals::MediaInternalsUMAHandler::GetUMANameForAVStream(
 void MediaInternals::MediaInternalsUMAHandler::ReportUMAForPipelineStatus(
     const PipelineInfo& player_info) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // Don't log pipeline status for players which don't actually have a pipeline;
+  // e.g., the Android MediaSourcePlayer implementation.
+  if (!player_info.has_pipeline)
+    return;
+
   if (player_info.has_video && player_info.has_audio) {
     base::LinearHistogram::FactoryGet(
         GetUMANameForAVStream(player_info), 1, media::PIPELINE_STATUS_MAX,