media: Add Media.EME.MediaCryptoAvailable UMA

Bug: 840586
Change-Id: I0d91bde150d6e3755df3a3577862149298eaa61f
Reviewed-on: https://chromium-review.googlesource.com/1050934Reviewed-by: Frank Liberato <liberato@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557469}

media/base/android/media_drm_bridge.cc

@@ -19,6 +19,7 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ -948,6 +949,9 @@ void MediaDrmBridge::NotifyMediaCryptoReady(JavaObjectPtr j_media_crypto) {
 
   j_media_crypto_ = std::move(j_media_crypto);
 
+  UMA_HISTOGRAM_BOOLEAN("Media.EME.MediaCryptoAvailable",
+                        !j_media_crypto_->is_null());
+
   if (media_crypto_ready_cb_.is_null())
     return;
 

tools/metrics/histograms/histograms.xml

@@ -37208,6 +37208,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Media.EME.MediaCryptoAvailable" enum="BooleanAvailable">
+  <owner>media-dev@chromium.org</owner>
+  <summary>
+    Whether MediaCrypto is available on a MediaDrm-based CDM. Reported once per
+    MediaDrmBridge creation. In normal cases it should always be available.
+  </summary>
+</histogram>
+
 <histogram name="Media.EME.MojoCdm.ConnectionError"
     enum="BooleanConnectionError">
   <owner>media-dev@chromium.org</owner>