[Media>UI] Migrate media notification tests to JUnit tests

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 f1b70d18b607139fd3c096d3b40c165bc45c44f9..2cdd8c5da5f2e5c2d70f97647ed35d34617299a4 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
@@ -41,14 +41,16 @@ public class MediaSessionTabHelper implements MediaImageCallback {
     private static final String TAG = "MediaSession";
 
     private static final String UNICODE_PLAY_CHARACTER = "\u25B6";
-    private static final int HIDE_NOTIFICATION_DELAY_MILLIS = 1000;
+    @VisibleForTesting
+    static final int HIDE_NOTIFICATION_DELAY_MILLIS = 1000;
 
     private Tab mTab;
     private Bitmap mPageMediaImage;
     private Bitmap mFavicon;
     private Bitmap mCurrentMediaImage;
     private String mOrigin;
-    private MediaSessionObserver mMediaSessionObserver;
+    @VisibleForTesting
+    MediaSessionObserver mMediaSessionObserver;
     private int mPreviousVolumeControlStream = AudioManager.USE_DEFAULT_STREAM_TYPE;
     private MediaNotificationInfo.Builder mNotificationInfoBuilder;
     // The fallback title if |mPageMetadata| is null or its title is empty.
@@ -65,6 +67,11 @@ public class MediaSessionTabHelper implements MediaImageCallback {
     // showing or immediate hiding.
     private Runnable mHideNotificationDelayedTask;
 
+    // Used to override the MediaSession object get from WebContents. This is to work around the
+    // static getter {@link MediaSession#fromWebContents()}.
+    @VisibleForTesting
+    static MediaSession sOverriddenMediaSession;
+
     @VisibleForTesting
     @Nullable
     MediaSessionObserver getMediaSessionObserverForTesting() {
@@ -244,7 +251,7 @@ public class MediaSessionTabHelper implements MediaImageCallback {
     }
 
     private void setWebContents(WebContents webContents) {
-        MediaSession mediaSession = MediaSession.fromWebContents(webContents);
+        MediaSession mediaSession = getMediaSession(webContents);
         if (mMediaSessionObserver != null
                 && mediaSession == mMediaSessionObserver.getMediaSession()) {
             return;
@@ -264,7 +271,8 @@ public class MediaSessionTabHelper implements MediaImageCallback {
         mMediaSessionActions = null;
     }
 
-    private final TabObserver mTabObserver = new EmptyTabObserver() {
+    @VisibleForTesting
+    final TabObserver mTabObserver = new EmptyTabObserver() {
         @Override
         public void onContentChanged(Tab tab) {
             assert tab == mTab;
@@ -292,7 +300,9 @@ public class MediaSessionTabHelper implements MediaImageCallback {
             String origin = mTab.getUrl();
             try {
                 origin = UrlFormatter.formatUrlForSecurityDisplay(new URI(origin), true);
-            } catch (URISyntaxException e) {
+            } catch (URISyntaxException | UnsatisfiedLinkError e) {
+                // UnstatisfiedLinkError can only happen in tests as the natives are not initialized
+                // yet.
                 Log.e(TAG, "Unable to parse the origin from the URL. "
                                 + "Using the full URL instead.");
             }
@@ -348,7 +358,8 @@ public class MediaSessionTabHelper implements MediaImageCallback {
         }
     };
 
-    private MediaSessionTabHelper(Tab tab) {
+    @VisibleForTesting
+    MediaSessionTabHelper(Tab tab) {
         mTab = tab;
         mTab.addObserver(mTabObserver);
         mMediaImageManager =
@@ -498,4 +509,9 @@ public class MediaSessionTabHelper implements MediaImageCallback {
     private boolean isNotificationHiddingOrHidden() {
         return mNotificationInfoBuilder == null;
     }
+
+    private MediaSession getMediaSession(WebContents contents) {
+        return (sOverriddenMediaSession != null) ? sOverriddenMediaSession
+                                                 : MediaSession.fromWebContents(contents);
+    }
 }