-Added toggle for enabling leak canary heap dump.

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

@@ -5,6 +5,7 @@ import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.content.Context;
 import android.os.Build;
+import android.support.annotation.Nullable;
 import android.util.Log;
 
 import com.nostra13.universalimageloader.cache.memory.impl.LRULimitedMemoryCache;
@@ -167,6 +168,7 @@ public class App extends Application {
         mNotificationManager.createNotificationChannel(mChannel);
     }
 
+    @Nullable
     public static RefWatcher getRefWatcher(Context context) {
         final App application = (App) context.getApplicationContext();
         return application.refWatcher;

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

@@ -71,8 +71,9 @@ public abstract class BaseFragment extends Fragment {
     @Override
     public void onDestroy() {
         super.onDestroy();
+
         RefWatcher refWatcher = App.getRefWatcher(getActivity());
-        refWatcher.watch(this);
+        if (refWatcher != null) refWatcher.watch(this);
     }
 
     /*//////////////////////////////////////////////////////////////////////////

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

@@ -211,6 +211,12 @@ public class MainActivity extends AppCompatActivity {
         }
     }
 
+    private void onHeapDumpToggled(@NonNull MenuItem item) {
+        final boolean newToggleState = !item.isChecked();
+        sharedPreferences.edit().putBoolean(getString(R.string.allow_heap_dumping_key),
+                newToggleState).apply();
+        item.setChecked(newToggleState);
+    }
     /*//////////////////////////////////////////////////////////////////////////
     // Menu
     //////////////////////////////////////////////////////////////////////////*/
@@ -232,6 +238,10 @@ public class MainActivity extends AppCompatActivity {
             inflater.inflate(R.menu.main_menu, menu);
         }
 
+        if (DEBUG) {
+            getMenuInflater().inflate(R.menu.debug_menu, menu);
+        }
+
         ActionBar actionBar = getSupportActionBar();
         if (actionBar != null) {
             actionBar.setDisplayHomeAsUpEnabled(false);
@@ -242,6 +252,17 @@ public class MainActivity extends AppCompatActivity {
         return true;
     }
 
+    @Override
+    public boolean onPrepareOptionsMenu(Menu menu) {
+        MenuItem heapDumpToggle = menu.findItem(R.id.action_toggle_heap_dump);
+        if (heapDumpToggle != null) {
+            final boolean isToggled = sharedPreferences.getBoolean(
+                    getString(R.string.allow_heap_dumping_key), false);
+            heapDumpToggle.setChecked(isToggled);
+        }
+        return super.onPrepareOptionsMenu(menu);
+    }
+
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         if (DEBUG) Log.d(TAG, "onOptionsItemSelected() called with: item = [" + item + "]");
@@ -262,6 +283,9 @@ public class MainActivity extends AppCompatActivity {
             case R.id.action_history:
                 NavigationHelper.openHistory(this);
                 return true;
+            case R.id.action_toggle_heap_dump:
+                onHeapDumpToggled(item);
+                return true;
             default:
                 return super.onOptionsItemSelected(item);
         }

app/src/main/res/menu/debug_menu.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item android:id="@+id/action_toggle_heap_dump"
+        android:orderInCategory="9999"
+        android:checkable="true"
+        android:title="@string/toggle_leak_canary"
+        android:visible="true"
+        app:showAsAction="never"/>
+
+</menu>

app/src/main/res/values/settings_keys.xml

@@ -83,6 +83,9 @@
 
     <string name="last_orientation_landscape_key" translatable="false">last_orientation_landscape_key</string>
 
+    <!-- DEBUG ONLY -->
+    <string name="allow_heap_dumping_key" translatable="false">allow_heap_dumping_key</string>
+
     <!-- THEMES -->
     <string name="theme_key" translatable="false">theme</string>
     <string name="light_theme_key" translatable="false">light_theme</string>

app/src/main/res/values/strings.xml

@@ -395,4 +395,7 @@
     <string name="playlist_add_stream_success">Added to playlist</string>
     <string name="playlist_thumbnail_change_success">Playlist thumbnail changed</string>
     <string name="playlist_delete_failure">Failed to delete playlist</string>
+
+    <!-- Debug Only -->
+    <string name="toggle_leak_canary">Leak Canary</string>
 </resources>