[MediaNotification] Fix a button computation issue with PLAY_PAUSE

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

Index: chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
index c2f190f070d2838648b233927084598496bf1911..1e4b3162e0a3bb5c759da98aa035e75876d25f0f 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
@@ -870,6 +870,7 @@ public class MediaNotificationManager {
         // https://crbug.com/667500
         if (mMediaNotificationInfo.supportsPlayPause()) {
             actions.addAll(mMediaNotificationInfo.mediaSessionActions);
+            actions.remove(MediaSessionAction.PLAY_PAUSE);
             if (mMediaNotificationInfo.isPaused) {
                 actions.remove(MediaSessionAction.PAUSE);
                 actions.add(MediaSessionAction.PLAY);
@@ -954,6 +955,8 @@ public class MediaNotificationManager {
         assert !actions.contains(MediaSessionAction.PLAY)
                 || !actions.contains(MediaSessionAction.PAUSE);
 
+        assert !actions.contains(MediaSessionAction.PLAY_PAUSE);
+
         int[] actionByOrder = {
                 MediaSessionAction.PREVIOUS_TRACK,
                 MediaSessionAction.SEEK_BACKWARD,
@@ -1018,6 +1021,8 @@ public class MediaNotificationManager {
         assert !actions.contains(MediaSessionAction.PLAY)
                 || !actions.contains(MediaSessionAction.PAUSE);
 
+        assert !actions.contains(MediaSessionAction.PLAY_PAUSE);
+
         if (actions.size() <= COMPACT_VIEW_ACTIONS_COUNT) {
             // If the number of actions is less than |COMPACT_VIEW_ACTIONS_COUNT|, just return an
             // array of 0, 1, ..., |actions.size()|-1.