iOS: Eliminate ScopedBlock, ScopedTypeRef, ScopedPolicy (#56410)

Eliminates the two remaining uses of ScopedBlock and with it, ScopedTypeRef which was only used by ScopedBlock. ARC automatically generates the necessary block copy/retain/release calls, including moving blocks to the heap during a retain so manual _Block_copy/_Block_release calls are no longer required.

No test changes since no semantic changes.

Issue: flutter/flutter#137801

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

Author: cbracken

ci/licenses_golden/licenses_flutter

@@ -42729,12 +42729,9 @@ ORIGIN: ../../../flutter/fml/platform/darwin/message_loop_darwin.mm + ../../../f
 ORIGIN: ../../../flutter/fml/platform/darwin/paths_darwin.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/platform_version.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/platform_version.mm + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/fml/platform/darwin/scoped_block.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/fml/platform/darwin/scoped_block.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/scoped_policy.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/fml/platform/darwin/scoped_typeref.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/string_range_sanitization.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/darwin/string_range_sanitization.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/fml/platform/fuchsia/log_interest_listener.cc + ../../../flutter/LICENSE
@@ -45592,12 +45589,9 @@ FILE: ../../../flutter/fml/platform/darwin/message_loop_darwin.mm
 FILE: ../../../flutter/fml/platform/darwin/paths_darwin.mm
 FILE: ../../../flutter/fml/platform/darwin/platform_version.h
 FILE: ../../../flutter/fml/platform/darwin/platform_version.mm
-FILE: ../../../flutter/fml/platform/darwin/scoped_block.h
-FILE: ../../../flutter/fml/platform/darwin/scoped_block.mm
 FILE: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.cc
 FILE: ../../../flutter/fml/platform/darwin/scoped_nsautorelease_pool.h
 FILE: ../../../flutter/fml/platform/darwin/scoped_policy.h
-FILE: ../../../flutter/fml/platform/darwin/scoped_typeref.h
 FILE: ../../../flutter/fml/platform/darwin/string_range_sanitization.h
 FILE: ../../../flutter/fml/platform/darwin/string_range_sanitization.mm
 FILE: ../../../flutter/fml/platform/fuchsia/log_interest_listener.cc

fml/BUILD.gn

@@ -147,12 +147,9 @@ source_set("fml") {
       "platform/darwin/paths_darwin.mm",
       "platform/darwin/platform_version.h",
       "platform/darwin/platform_version.mm",
-      "platform/darwin/scoped_block.h",
-      "platform/darwin/scoped_block.mm",
       "platform/darwin/scoped_nsautorelease_pool.cc",
       "platform/darwin/scoped_nsautorelease_pool.h",
       "platform/darwin/scoped_policy.h",
-      "platform/darwin/scoped_typeref.h",
       "platform/darwin/string_range_sanitization.h",
       "platform/darwin/string_range_sanitization.mm",
     ]

fml/platform/darwin/scoped_block.h

@@ -9,7 +9,6 @@
 
 #include "flutter/fml/macros.h"
 #include "flutter/fml/make_copyable.h"
-#include "flutter/fml/platform/darwin/scoped_block.h"
 #include "flutter/fml/task_runner.h"
 #include "flutter/lib/ui/window/platform_message_response.h"
 #import "flutter/shell/platform/darwin/common/buffer_conversions.h"
@@ -30,7 +29,7 @@ class PlatformMessageResponseDarwin : public flutter::PlatformMessageResponse {
 
   ~PlatformMessageResponseDarwin() override;
 
-  fml::ScopedBlock<PlatformMessageResponseCallback> callback_;
+  PlatformMessageResponseCallback callback_;
   fml::RefPtr<fml::TaskRunner> platform_task_runner_;
 
   FML_FRIEND_MAKE_REF_COUNTED(PlatformMessageResponseDarwin);

fml/platform/darwin/scoped_block.mm

@@ -13,22 +13,20 @@
 PlatformMessageResponseDarwin::PlatformMessageResponseDarwin(
     PlatformMessageResponseCallback callback,
     fml::RefPtr<fml::TaskRunner> platform_task_runner)
-    : callback_(callback, fml::scoped_policy::OwnershipPolicy::kRetain),
-      platform_task_runner_(std::move(platform_task_runner)) {}
+    : callback_(callback), platform_task_runner_(std::move(platform_task_runner)) {}
 
 PlatformMessageResponseDarwin::~PlatformMessageResponseDarwin() = default;
 
 void PlatformMessageResponseDarwin::Complete(std::unique_ptr<fml::Mapping> data) {
   fml::RefPtr<PlatformMessageResponseDarwin> self(this);
   platform_task_runner_->PostTask(fml::MakeCopyable([self, data = std::move(data)]() mutable {
-    self->callback_.get()(CopyMappingPtrToNSData(std::move(data)));
+    self->callback_(CopyMappingPtrToNSData(std::move(data)));
   }));
 }
 
 void PlatformMessageResponseDarwin::CompleteEmpty() {
   fml::RefPtr<PlatformMessageResponseDarwin> self(this);
-  platform_task_runner_->PostTask(
-      fml::MakeCopyable([self]() mutable { self->callback_.get()(nil); }));
+  platform_task_runner_->PostTask(fml::MakeCopyable([self]() mutable { self->callback_(nil); }));
 }
 
 }  // namespace flutter

fml/platform/darwin/scoped_typeref.h

@@ -5,7 +5,6 @@
 #ifndef FLUTTER_SHELL_PLATFORM_DARWIN_IOS_PLATFORM_MESSAGE_HANDLER_IOS_H_
 #define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_PLATFORM_MESSAGE_HANDLER_IOS_H_
 
-#include "flutter/fml/platform/darwin/scoped_block.h"
 #include "flutter/fml/task_runner.h"
 #include "flutter/shell/common/platform_message_handler.h"
 #import "flutter/shell/platform/darwin/ios/flutter_task_queue_dispatch.h"
@@ -33,7 +32,7 @@ class PlatformMessageHandlerIos : public PlatformMessageHandler {
 
   struct HandlerInfo {
     NSObject<FlutterTaskQueueDispatch>* task_queue;
-    fml::ScopedBlock<FlutterBinaryMessageHandler> handler;
+    FlutterBinaryMessageHandler handler;
   };
 
  private:

shell/platform/darwin/ios/framework/Source/platform_message_response_darwin.h

@@ -125,9 +125,7 @@ - (void)dispatch:(dispatch_block_t)block {
   if (handler) {
     message_handlers_[channel] = {
         .task_queue = (NSObject<FlutterTaskQueueDispatch>*)task_queue,
-        .handler =
-            fml::ScopedBlock<FlutterBinaryMessageHandler>{
-                handler, fml::scoped_policy::OwnershipPolicy::kRetain},
+        .handler = handler,
     };
   }
 }