Remove deprecated (#9474)

packages/flutter/lib/src/widgets/framework.dart

@@ -740,12 +740,6 @@ abstract class State<T extends StatefulWidget> {
   T get widget => _widget;
   T _widget;
 
-  /// Deprecated getter for [widget]. Use the [widget] getter instead. This
-  /// getter will be removed on 2017/04/20.
-  @Deprecated('The "config" property is now called "widget". Please migrate '
-      'now, as we will remove this feature soon.')
-  T get config => _widget;
-
   /// The current stage in the lifecycle for this state object.
   ///
   /// This field is used by the framework when asserts are enabled to verify
@@ -836,13 +830,6 @@ abstract class State<T extends StatefulWidget> {
   @protected
   void didUpdateWidget(covariant T oldWidget) { }
 
-  /// Deprecated callback when the widget configuration changes.
-  ///
-  /// Use [didUpdateWidget] instead. This method will be removed on 2017/04/20.
-  @Deprecated('The "didUpdateConfig" method is now called "didUpdateWidget". '
-      'Please migrate now, as we will remove this feature soon.')
-  void didUpdateConfig(covariant T oldConfig) { }
-
   /// Called whenever the application is reassembled during debugging.
   ///
   /// This method should rerun any initialization logic that depends on global
@@ -3288,8 +3275,6 @@ class StatefulElement extends ComponentElement {
     try {
       _debugSetAllowIgnoredCallsToMarkNeedsBuild(true);
       _state.didUpdateWidget(oldWidget);
-      // ignore: deprecated_member_use
-      _state.didUpdateConfig(oldWidget);
     } finally {
       _debugSetAllowIgnoredCallsToMarkNeedsBuild(false);
     }