From 11d0020dd63da4a3d4c5f92025596b17ea36eb95 Mon Sep 17 00:00:00 2001
From: Emmanuel Garcia <egarciad@google.com>
Date: Tue, 24 Mar 2020 20:10:10 -0700
Subject: [PATCH] Flush background canvas before allocating a new surface
 (flutter/engine#17308)

---
 .../darwin/ios/framework/Source/FlutterPlatformViews.mm        | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
index b96fcbbbaa7..32c91c91e40 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
@@ -451,6 +451,9 @@ bool FlutterPlatformViewsController::SubmitFrame(GrContext* gr_context,
                                                  std::shared_ptr<IOSContext> ios_context,
                                                  SkCanvas* background_canvas) {
   DisposeViews();
+
+  // Resolve all pending GPU operations before allocating a new surface.
+  background_canvas->flush();
   // Clipping the background canvas before drawing the picture recorders requires to
   // save and restore the clip context.
   SkAutoCanvasRestore save(background_canvas, /*doSave=*/true);