-Added LeakCanary to debug build for memory detection on activities and fragments.

-Added LeakCanary no-op lib to release and beta builds.

app/src/main/java/org/schabi/newpipe/App.java

@@ -10,6 +10,8 @@ import android.util.Log;
 import com.nostra13.universalimageloader.cache.memory.impl.LRULimitedMemoryCache;
 import com.nostra13.universalimageloader.core.ImageLoader;
 import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
+import com.squareup.leakcanary.LeakCanary;
+import com.squareup.leakcanary.RefWatcher;
 
 import org.acra.ACRA;
 import org.acra.config.ACRAConfiguration;
@@ -54,6 +56,7 @@ import io.reactivex.plugins.RxJavaPlugins;
 
 public class App extends Application {
     protected static final String TAG = App.class.toString();
+    private RefWatcher refWatcher;
 
     @SuppressWarnings("unchecked")
     private static final Class<? extends ReportSenderFactory>[] reportSenderFactoryClasses = new Class[]{AcraReportSenderFactory.class};
@@ -69,6 +72,13 @@ public class App extends Application {
     public void onCreate() {
         super.onCreate();
 
+        if (LeakCanary.isInAnalyzerProcess(this)) {
+            // This process is dedicated to LeakCanary for heap analysis.
+            // You should not init your app in this process.
+            return;
+        }
+        refWatcher = installLeakCanary();
+
         // Initialize settings first because others inits can use its values
         SettingsActivity.initSettings(this);
 
@@ -157,4 +167,12 @@ public class App extends Application {
         mNotificationManager.createNotificationChannel(mChannel);
     }
 
+    public static RefWatcher getRefWatcher(Context context) {
+        final App application = (App) context.getApplicationContext();
+        return application.refWatcher;
+    }
+
+    protected RefWatcher installLeakCanary() {
+        return RefWatcher.DISABLED;
+    }
 }