[Media, UI] Don't record click UMA when content intent is null

BUG=607397

Review-Url: https://codereview.chromium.org/1927863003
Cr-Commit-Position: refs/heads/master@{#390351}

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java

@@ -142,8 +142,10 @@ public class CastSessionImpl implements MediaNotificationListener, CastSession {
         }
 
         Intent contentIntent = Tab.createBringTabToFrontIntent(tabId);
-        contentIntent.putExtra(MediaNotificationUma.INTENT_EXTRA_NAME,
-                MediaNotificationUma.SOURCE_PRESENTATION);
+        if (contentIntent != null) {
+            contentIntent.putExtra(MediaNotificationUma.INTENT_EXTRA_NAME,
+                    MediaNotificationUma.SOURCE_PRESENTATION);
+        }
         mNotificationBuilder = new MediaNotificationInfo.Builder()
                 .setPaused(false)
                 .setOrigin(origin)

chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java

@@ -114,8 +114,10 @@ public class MediaSessionTabHelper {
                 }
 
                 Intent contentIntent = Tab.createBringTabToFrontIntent(mTab.getId());
-                contentIntent.putExtra(MediaNotificationUma.INTENT_EXTRA_NAME,
-                        MediaNotificationUma.SOURCE_MEDIA);
+                if (contentIntent != null) {
+                    contentIntent.putExtra(MediaNotificationUma.INTENT_EXTRA_NAME,
+                            MediaNotificationUma.SOURCE_MEDIA);
+                }
 
                 mNotificationInfoBuilder =
                         new MediaNotificationInfo.Builder()