[MediaNotification] Add UMA to record user clicking media notifications

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

Index: chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java
index 3339a72a1a560c28ada98bc4b75adfbdc26d27d5..cbe79ff8e27b858298a401b4ae85172d565bf675 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CastSessionImpl.java
@@ -21,6 +21,7 @@ import org.chromium.chrome.R;
 import org.chromium.chrome.browser.media.ui.MediaNotificationInfo;
 import org.chromium.chrome.browser.media.ui.MediaNotificationListener;
 import org.chromium.chrome.browser.media.ui.MediaNotificationManager;
+import org.chromium.chrome.browser.metrics.LaunchFromNotificationUMA;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.content_public.common.MediaMetadata;
 
@@ -139,17 +140,21 @@ public class CastSessionImpl implements MediaNotificationListener, CastSession {
                     });
         }
 
-        mNotificationBuilder = new MediaNotificationInfo.Builder()
-                .setPaused(false)
-                .setOrigin(origin)
-                // TODO(avayvod): the same session might have more than one tab id. Should we track
-                // the last foreground alive tab and update the notification with it?
-                .setTabId(tabId)
-                .setPrivate(isIncognito)
-                .setActions(MediaNotificationInfo.ACTION_STOP)
-                .setContentIntent(Tab.createBringTabToFrontIntent(tabId))
-                .setId(R.id.presentation_notification)
-                .setListener(this);
+        mNotificationBuilder =
+                new MediaNotificationInfo.Builder()

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

Undo this extra indentation.  The change doesn't help readability at all.

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

Done.

+                        .setPaused(false)
+                        .setOrigin(origin)
+                        // TODO(avayvod): the same session might have more than one tab id. Should
+                        // we track
+                        // the last foreground alive tab and update the notification with it?
+                        .setTabId(tabId)
+                        .setPrivate(isIncognito)
+                        .setActions(MediaNotificationInfo.ACTION_STOP)
+                        .setContentIntent(Tab.createBringTabToFrontIntent(tabId).putExtra(

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

This is hard to read.  Temporarily store the Intent as another variable before
constructing the Builder instead of adding yet another level of indentation.

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

Done.

+                                LaunchFromNotificationUMA.INTENT_EXTRA_NAME,
+                                LaunchFromNotificationUMA.SOURCE_PRESENTATION))
+                        .setId(R.id.presentation_notification)
+                        .setListener(this);
         setNotificationMetadata(mNotificationBuilder);
         MediaNotificationManager.show(context, mNotificationBuilder.build());
     }