Bug 1148092 - Telemetry for EME playback success/failure - r=cpearce,bsmedberg

dom/html/HTMLMediaElement.cpp

@@ -640,6 +640,14 @@ void HTMLMediaElement::ShutdownDecoder()
 
 void HTMLMediaElement::AbortExistingLoads()
 {
+#ifdef MOZ_EME
+  // If there is no existing decoder then we don't have anything to
+  // report. This prevents reporting the initial load from an
+  // empty video element as a failed EME load.
+  if (mDecoder) {
+    ReportEMETelemetry();
+  }
+#endif
   // Abort any already-running instance of the resource selection algorithm.
   mLoadWaitStatus = NOT_WAITING;
 
@@ -2541,6 +2549,20 @@ nsresult HTMLMediaElement::BindToTree(nsIDocument* aDocument, nsIContent* aParen
   return rv;
 }
 
+#ifdef MOZ_EME
+void
+HTMLMediaElement::ReportEMETelemetry()
+{
+  // Report telemetry for EME videos when a page is unloaded.
+  NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
+  if (mIsEncrypted && Preferences::GetBool("media.eme.enabled")) {
+    Telemetry::Accumulate(Telemetry::VIDEO_EME_PLAY_SUCCESS, mLoadedDataFired);
+    LOG(PR_LOG_DEBUG, ("%p VIDEO_EME_PLAY_SUCCESS = %s",
+                       this, mLoadedDataFired ? "true" : "false"));
+  }
+}
+#endif
+
 void
 HTMLMediaElement::ReportMSETelemetry()
 {
@@ -3781,6 +3803,9 @@ void HTMLMediaElement::SuspendOrResumeElement(bool aPauseElement, bool aSuspendE
     if (aPauseElement) {
       if (mMediaSource) {
         ReportMSETelemetry();
+#ifdef MOZ_EME
+        ReportEMETelemetry();
+#endif
       }
 
 #ifdef MOZ_EME

dom/html/HTMLMediaElement.h

@@ -978,6 +978,9 @@ protected:
     return isPaused;
   }
 
+#ifdef MOZ_EME
+  void ReportEMETelemetry();
+#endif
   void ReportMSETelemetry();
 
   // Check the permissions for audiochannel.

toolkit/components/telemetry/Histograms.json

@@ -7469,6 +7469,11 @@
     "n_buckets": 16,
     "description": "The number of entries in persistent DataStorage (HSTS and HPKP data, basically)"
   },
+  "VIDEO_EME_PLAY_SUCCESS": {
+    "expires_in_version": "45",
+    "kind": "boolean",
+    "description": "EME video playback success or failure"
+  },
   "VIDEO_MSE_JOIN_LATENCY_MS" : {
     "expires_in_version": "45",
     "description": "Time in MS between MSE video load and playback",