Get active Context from the Registrar (flutter#4523)

AUTHORS

@@ -5,3 +5,4 @@
 
 Google Inc.
 Jim Simon <[email protected]>
+Ali Bitek <[email protected]>

shell/platform/android/io/flutter/app/FlutterPluginRegistry.java

@@ -92,6 +92,11 @@ public Context context() {
             return mAppContext;
         }
 
+        @Override
+        public Context activeContext() {
+            return (mActivity != null) ? mActivity : mAppContext;
+        }
+
         @Override
         public BinaryMessenger messenger() {
             return mNativeView;

shell/platform/android/io/flutter/plugin/common/PluginRegistry.java

@@ -80,6 +80,13 @@ interface Registrar {
          */
         Context context();
 
+        /**
+        * Returns the active {@link Context}.
+        *
+        * @return the current {@link #activity() Activity}, if not null, otherwise the {@link #context() Application}.
+        */
+        Context activeContext();
+
         /**
          * Returns a {@link BinaryMessenger} which the plugin can use for
          * creating channels for communicating with the Dart side.