[MediaNotification] Add UMA to record user clicking media notifications

chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
index 367f884794d64521d6dc374b6fd6e124033ceeed..a5a9b19a92c8b6505a0e98133bd4b789d6f38860 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java
@@ -50,6 +50,7 @@ import org.chromium.chrome.browser.customtabs.SeparateTaskCustomTabActivity;
 import org.chromium.chrome.browser.externalnav.IntentWithGesturesHandler;
 import org.chromium.chrome.browser.firstrun.FirstRunFlowSequencer;
 import org.chromium.chrome.browser.metrics.LaunchMetrics;
+import org.chromium.chrome.browser.metrics.MediaNotificationUma;
 import org.chromium.chrome.browser.metrics.StartupMetrics;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.notifications.NotificationUIManager;
@@ -984,5 +985,6 @@ public class ChromeLauncherActivity extends Activity
             int maskedFlags = intent.getFlags() & flagsOfInterest;
             sIntentFlagsHistogram.record(maskedFlags);
         }
+        MediaNotificationUma.recordClickSource(intent);
     }
 }