[MediaNotification] Add UMA to record user clicking media notifications

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

Index: chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java
index 04d3061dbddddf48b5cb4477b99387f510113d4f..9e67fed12f5c5eca15dbd0e0bab2c6e820ea6af4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java
@@ -14,6 +14,7 @@ import org.chromium.base.ApplicationStatus;
 import org.chromium.base.Log;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeFeatureList;
+import org.chromium.chrome.browser.metrics.LaunchFromNotificationUMA;
 import org.chromium.chrome.browser.metrics.MediaSessionUMA;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
@@ -122,7 +123,11 @@ public class MediaSessionTabHelper {
                                 .setLargeIcon(mFavicon)
                                 .setActions(MediaNotificationInfo.ACTION_PLAY_PAUSE
                                         | MediaNotificationInfo.ACTION_SWIPEAWAY)
-                                .setContentIntent(Tab.createBringTabToFrontIntent(mTab.getId()))
+                                .setContentIntent(
+                                        Tab.createBringTabToFrontIntent(mTab.getId())

[gone, 2016/04/20 22:17:14]

Same comment about formatting as above.  This is indented a rather ridiculous 5
levels deep now.  Store the Intent before the builder is called and edit it
there.

[Zhiqiang Zhang (Slow), 2016/04/21 16:36:52]

Done.

+                                                .putExtra(
+                                                        LaunchFromNotificationUMA.INTENT_EXTRA_NAME,
+                                                        LaunchFromNotificationUMA.SOURCE_MEDIA))
                                 .setId(R.id.media_playback_notification)
                                 .setListener(mControlsListener);