Revert "Delegate AppDelegate life-cycle callbacks to plugins via sepa…

…rate object (flutter#5173)" (flutter#5294)

This reverts commit 597fa9e as it broke
mac engine build bot.

shell/platform/darwin/ios/BUILD.gn

@@ -22,7 +22,6 @@ _flutter_framework_headers = [
   "framework/Headers/FlutterMacros.h",
   "framework/Headers/FlutterNavigationController.h",
   "framework/Headers/FlutterPlugin.h",
-  "framework/Headers/FlutterPluginAppLifeCycleDelegate.h",
   "framework/Headers/FlutterTexture.h",
   "framework/Headers/FlutterViewController.h",
 ]
@@ -44,7 +43,6 @@ shared_library("create_flutter_framework_dylib") {
     "framework/Source/FlutterNavigationController.mm",
     "framework/Source/FlutterPlatformPlugin.h",
     "framework/Source/FlutterPlatformPlugin.mm",
-    "framework/Source/FlutterPluginAppLifeCycleDelegate.mm",
     "framework/Source/FlutterStandardCodec.mm",
     "framework/Source/FlutterStandardCodec_Internal.h",
     "framework/Source/FlutterTextInputDelegate.h",

shell/platform/darwin/ios/framework/Headers/Flutter.h

@@ -43,7 +43,6 @@
 #include "FlutterMacros.h"
 #include "FlutterNavigationController.h"
 #include "FlutterPlugin.h"
-#include "FlutterPluginAppLifeCycleDelegate.h"
 #include "FlutterTexture.h"
 #include "FlutterViewController.h"
 

shell/platform/darwin/ios/framework/Headers/FlutterAppDelegate.h

@@ -24,10 +24,22 @@
  * code as necessary from FlutterAppDelegate.mm.
  */
 FLUTTER_EXPORT
-@interface FlutterAppDelegate : UIResponder<UIApplicationDelegate, FlutterPluginRegistry, FlutterAppLifeCycleProvider>
+@interface FlutterAppDelegate : UIResponder<UIApplicationDelegate, FlutterPluginRegistry>
 
 @property(strong, nonatomic) UIWindow* window;
 
+// Can be overriden by subclasses to provide a custom FlutterBinaryMessenger,
+// typically a FlutterViewController, for plugin interop.
+//
+// Defaults to window's rootViewController.
+- (NSObject<FlutterBinaryMessenger>*)binaryMessenger;
+
+// Can be overriden by subclasses to provide a custom FlutterTextureRegistry,
+// typically a FlutterViewController, for plugin interop.
+//
+// Defaults to window's rootViewController.
+- (NSObject<FlutterTextureRegistry>*)textures;
+
 @end
 
 #endif  // FLUTTER_FLUTTERDARTPROJECT_H_

shell/platform/darwin/ios/framework/Headers/FlutterPlugin.h

@@ -253,14 +253,6 @@ NS_ASSUME_NONNULL_BEGIN
 - (NSObject*)valuePublishedByPlugin:(NSString*)pluginKey;
 @end
 
-/**
- Implement this in the `UIAppDelegate` of your app to enable Flutter plugins to register themselves to the application
- life cycle events.
-*/
-@protocol FlutterAppLifeCycleProvider
-- (void)addApplicationLifeCycleDelegate:(NSObject<FlutterPlugin>*)delegate;
-@end
-
 NS_ASSUME_NONNULL_END;
 
 #endif  // FLUTTER_FLUTTERPLUGIN_H_

shell/platform/darwin/ios/framework/Headers/FlutterViewController.h

@@ -11,11 +11,10 @@
 #include "FlutterBinaryMessenger.h"
 #include "FlutterDartProject.h"
 #include "FlutterMacros.h"
-#include "FlutterPlugin.h"
 #include "FlutterTexture.h"
 
 FLUTTER_EXPORT
-@interface FlutterViewController : UIViewController<FlutterBinaryMessenger, FlutterTextureRegistry, FlutterPluginRegistry>
+@interface FlutterViewController : UIViewController<FlutterBinaryMessenger, FlutterTextureRegistry>
 
 - (instancetype)initWithProject:(FlutterDartProject*)project
                         nibName:(NSString*)nibNameOrNil
@@ -50,8 +49,6 @@ FLUTTER_EXPORT
  */
 - (void)setInitialRoute:(NSString*)route;
 
-- (id<FlutterPluginRegistry>)pluginRegistry;
-
 @end
 
 #endif  // FLUTTER_FLUTTERVIEWCONTROLLER_H_