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[iOS] Remove dead RasterThreadMerger plumbing from platform views#189753

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cbracken merged 1 commit into
flutter:masterfrom
cbracken:embedder-pw-1
Jul 22, 2026
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[iOS] Remove dead RasterThreadMerger plumbing from platform views#189753
cbracken merged 1 commit into
flutter:masterfrom
cbracken:embedder-pw-1

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@cbracken

@cbracken cbracken commented Jul 21, 2026

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IOSExternalViewEmbedder::SupportsDynamicThreadMerging() returns false, so the raster thread merger is never engaged on iOS.

This deletes two no-op overrides in FlutterPlatformViewsController:

  • postPrerollActionWithThreadMerger: ignores its merger argument and unconditionally returns PostPrerollResult::kSuccess, which is exactly the base-class default of ExternalViewEmbedder::PostPrerollAction.
  • `endFrameWithResubmit:threadMerger: has an empty body, matching the base-class default of ExternalViewEmbedder::EndFrame.

Also deletes the IOSExternalViewEmbedder overrides that existed only to forward to them. We now fall back to the base-class defaults which were identical. BeginFrame is pure virtual, so we still need its empty override. This removes fml::RefPtrfml::RasterThreadMerger and flutter::PostPrerollResult from the ObjC embedding surface.

This is pure no-op cleanup stemming from the fact that we now run only in thread-merged mode on iOS, and cleanup that makes an eventual migration to the embedder API easier.

No test changes since there are no semantic changes; covered by existing tests.

Issue: #112232

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IOSExternalViewEmbedder::SupportsDynamicThreadMerging() returns false, so
the raster thread merger is never engaged on iOS. 

This deletes two no-op overrides in FlutterPlatformViewsController:

* `postPrerollActionWithThreadMerger:` ignores its merger argument and
  unconditionally returns PostPrerollResult::kSuccess, which is exactly
  the base-class default of ExternalViewEmbedder::PostPrerollAction.
* `endFrameWithResubmit:threadMerger: has an empty body, matching the
  base-class default of ExternalViewEmbedder::EndFrame.

Also deletes the IOSExternalViewEmbedder overrides that existed only to
forward to them. We now fall back to the base-class defaults which were
identical. BeginFrame is pure virtual, so we still need its empty
override. This removes fml::RefPtr<fml::RasterThreadMerger> and
flutter::PostPrerollResult from the ObjC embedding surface.

This is pure no-op cleanup stemming from the fact that we now run only
in thread-merged mode on iOS, and cleanup that makes an eventual
migration to the embedder API easier.

Issue: flutter#112232
@cbracken
cbracken requested a review from a team as a code owner July 21, 2026 00:38
@flutter-dashboard flutter-dashboard Bot added the CICD Run CI/CD label Jul 21, 2026
@github-actions github-actions Bot added platform-ios iOS applications specifically engine flutter/engine related. See also e: labels. team-ios Owned by iOS platform team labels Jul 21, 2026

@gemini-code-assist gemini-code-assist Bot left a comment

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Code Review

This pull request removes the PostPrerollAction and EndFrame methods from IOSExternalViewEmbedder, along with the corresponding postPrerollActionWithThreadMerger: and endFrameWithResubmit:threadMerger: methods from FlutterPlatformViewsController. I have no feedback to provide as there are no review comments.

@stuartmorgan-g

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test-exempt: removing code

@hellohuanlin hellohuanlin left a comment

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LGTM!

@cbracken
cbracken added this pull request to the merge queue Jul 22, 2026
Merged via the queue into flutter:master with commit 3fa8815 Jul 22, 2026
30 checks passed
@cbracken
cbracken deleted the embedder-pw-1 branch July 22, 2026 01:35
auto-submit Bot pushed a commit to flutter/packages that referenced this pull request Jul 22, 2026
flutter/flutter@1ac2e82...2a2a79d

2026-07-22 [email protected] Clear cached directional focus history on a non-directional focus request  (flutter/flutter#187957)
2026-07-22 [email protected] ci: Include root pubspec.yaml in pub cache key (flutter/flutter#189826)
2026-07-22 [email protected] Remove codecov badge from README (flutter/flutter#189728)
2026-07-22 [email protected] Clean android engine/embedding tests (flutter/flutter#189276)
2026-07-22 [email protected] Add barrierBuilder support to showDialog and showGeneralDialog (flutter/flutter#187992)
2026-07-22 [email protected] Fix Mockito dynamic agent loading warnings in Robolectric tests (flutter/flutter#189804)
2026-07-22 [email protected] [iOS] Remove dead RasterThreadMerger plumbing from platform views (flutter/flutter#189753)
2026-07-22 [email protected] Add OverlayPortal.overlayChildLayoutBuilder sample (flutter/flutter#188930)
2026-07-22 [email protected] Automate recurring tasks via workflows - localizations (flutter/flutter#189750)
2026-07-21 [email protected] [iOS] Remove dead parameters and no-op overrides (flutter/flutter#189754)
2026-07-21 [email protected] [iOS] Inject DisplayLinkManager into FlutterViewController (flutter/flutter#189764)
2026-07-21 [email protected] Support custom BoxBorder animation in BoxDecoration (flutter/flutter#186348)
2026-07-21 [email protected] Rename CpuArch.x86_64 to CpuArch.x64 (flutter/flutter#189478)
2026-07-21 [email protected] Roll Skia from 569534e9fa59 to 5e183e5aeac5 (3 revisions) (flutter/flutter#189795)
2026-07-21 [email protected] Roll Dart SDK from 3b2f5ad7718d to 1e65011ee004 (4 revisions) (flutter/flutter#189791)
2026-07-21 [email protected] Run delete-bot-branches.yaml on `pull_request_target` instead of `pull_request` so that we can access secrets. (flutter/flutter#189793)
2026-07-21 [email protected] Batch release directory correction (flutter/flutter#189738)
2026-07-21 [email protected] [flutter_test][Test cross imports] Move TestWidgetsApp to flutter_test (flutter/flutter#189435)
2026-07-21 [email protected] Fix null-deref/double-dispose in StretchingOverscrollIndicator (#189589) (flutter/flutter#189667)
2026-07-21 [email protected] Roll Packages from 611899b to 8260a1e (10 revisions) (flutter/flutter#189782)
2026-07-21 [email protected] [iOS] Inject DisplayLinkManager into FlutterMetalLayer (flutter/flutter#189752)
2026-07-21 [email protected] Derive the SkImage size used by ImageEncodingImpeller::ConvertDlImageToSkImage from the size of the underlying texture, not the size of the DlImage (flutter/flutter#189739)

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