Make the resource context primary on iOS (#8387)

* Make resource context primary on iOS

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

@@ -33,7 +33,7 @@
 
 - (instancetype)initWithDelegate:(id<FlutterViewEngineDelegate>)delegate
                           opaque:(BOOL)opaque NS_DESIGNATED_INITIALIZER;
-- (std::unique_ptr<shell::IOSSurface>)createSurface;
+- (std::unique_ptr<shell::IOSSurface>)createSurface:(std::shared_ptr<shell::IOSGLContext>)context;
 
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterView.mm

@@ -75,7 +75,7 @@ id<FlutterViewEngineDelegate> _delegate;
 #endif  // TARGET_IPHONE_SIMULATOR
 }
 
-- (std::unique_ptr<shell::IOSSurface>)createSurface {
+- (std::unique_ptr<shell::IOSSurface>)createSurface:(std::shared_ptr<shell::IOSGLContext>)context {
   if ([self.layer isKindOfClass:[CAEAGLLayer class]]) {
     fml::scoped_nsobject<CAEAGLLayer> eagl_layer(
         reinterpret_cast<CAEAGLLayer*>([self.layer retain]));
@@ -88,7 +88,7 @@ id<FlutterViewEngineDelegate> _delegate;
         eagl_layer.get().presentsWithTransaction = YES;
       }
     }
-    return std::make_unique<shell::IOSSurfaceGL>(std::move(eagl_layer),
+    return std::make_unique<shell::IOSSurfaceGL>(context, std::move(eagl_layer),
                                                  [_delegate platformViewsController]);
   } else {
     fml::scoped_nsobject<CALayer> layer(reinterpret_cast<CALayer*>([self.layer retain]));

shell/platform/darwin/ios/ios_gl_context.mm

@@ -13,14 +13,14 @@
 namespace shell {
 
 IOSGLContext::IOSGLContext() {
-  context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3]);
-  if (context_ != nullptr) {
-    resource_context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3
-                                                  sharegroup:context_.get().sharegroup]);
+  resource_context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3]);
+  if (resource_context_ != nullptr) {
+    context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3
+                                         sharegroup:resource_context_.get().sharegroup]);
   } else {
-    context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]);
-    resource_context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2
-                                                  sharegroup:context_.get().sharegroup]);
+    resource_context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]);
+    context_.reset([[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2
+                                         sharegroup:resource_context_.get().sharegroup]);
   }
 
   // TODO:

shell/platform/darwin/ios/ios_surface_gl.h

@@ -20,7 +20,8 @@ class IOSSurfaceGL : public IOSSurface,
                      public GPUSurfaceGLDelegate,
                      public flow::ExternalViewEmbedder {
  public:
-  IOSSurfaceGL(fml::scoped_nsobject<CAEAGLLayer> layer,
+  IOSSurfaceGL(std::shared_ptr<IOSGLContext> context,
+               fml::scoped_nsobject<CAEAGLLayer> layer,
                FlutterPlatformViewsController* platform_views_controller);
 
   IOSSurfaceGL(fml::scoped_nsobject<CAEAGLLayer> layer, std::shared_ptr<IOSGLContext> context);

shell/platform/darwin/ios/ios_surface_gl.mm

@@ -9,10 +9,10 @@
 
 namespace shell {
 
-IOSSurfaceGL::IOSSurfaceGL(fml::scoped_nsobject<CAEAGLLayer> layer,
+IOSSurfaceGL::IOSSurfaceGL(std::shared_ptr<IOSGLContext> context,
+                           fml::scoped_nsobject<CAEAGLLayer> layer,
                            FlutterPlatformViewsController* platform_views_controller)
-    : IOSSurface(platform_views_controller) {
-  context_ = std::make_shared<IOSGLContext>();
+    : IOSSurface(platform_views_controller), context_(context) {
   render_target_ = context_->CreateRenderTarget(std::move(layer));
 }
 
@@ -29,7 +29,7 @@ bool IOSSurfaceGL::IsValid() const {
 }
 
 bool IOSSurfaceGL::ResourceContextMakeCurrent() {
-  return render_target_->IsValid() ? context_->ResourceMakeCurrent() : false;
+  return context_->ResourceMakeCurrent();
 }
 
 void IOSSurfaceGL::UpdateStorageSizeIfNecessary() {

shell/platform/darwin/ios/platform_view_ios.h

@@ -17,6 +17,7 @@
 #include "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/accessibility_bridge.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/platform_message_router.h"
+#include "flutter/shell/platform/darwin/ios/ios_gl_context.h"
 #include "flutter/shell/platform/darwin/ios/ios_surface.h"
 
 @class FlutterViewController;
@@ -46,6 +47,7 @@ class PlatformViewIOS final : public PlatformView {
  private:
   fml::WeakPtr<FlutterViewController> owner_controller_;
   std::unique_ptr<IOSSurface> ios_surface_;
+  std::shared_ptr<IOSGLContext> gl_context_;
   PlatformMessageRouter platform_message_router_;
   std::unique_ptr<AccessibilityBridge> accessibility_bridge_;
   fml::scoped_nsprotocol<FlutterTextInputPlugin*> text_input_plugin_;

shell/platform/darwin/ios/platform_view_ios.mm

@@ -20,7 +20,11 @@
 namespace shell {
 
 PlatformViewIOS::PlatformViewIOS(PlatformView::Delegate& delegate, blink::TaskRunners task_runners)
-    : PlatformView(delegate, std::move(task_runners)) {}
+    : PlatformView(delegate, std::move(task_runners)) {
+#if !TARGET_IPHONE_SIMULATOR
+  gl_context_ = std::make_shared<IOSGLContext>();
+#endif  // !TARGET_IPHONE_SIMULATOR
+}
 
 PlatformViewIOS::~PlatformViewIOS() = default;
 
@@ -45,7 +49,8 @@ void PlatformViewIOS::SetOwnerViewController(fml::WeakPtr<FlutterViewController>
   }
   owner_controller_ = owner_controller;
   if (owner_controller_) {
-    ios_surface_ = static_cast<FlutterView*>(owner_controller.get().view).createSurface;
+    ios_surface_ =
+        [static_cast<FlutterView*>(owner_controller.get().view) createSurface:gl_context_];
     FML_DCHECK(ios_surface_ != nullptr);
 
     if (accessibility_bridge_) {
@@ -77,10 +82,10 @@ std::unique_ptr<Surface> PlatformViewIOS::CreateRenderingSurface() {
 
 // |shell::PlatformView|
 sk_sp<GrContext> PlatformViewIOS::CreateResourceContext() const {
-  if (!ios_surface_ || !ios_surface_->ResourceContextMakeCurrent()) {
+  if (!gl_context_ || !gl_context_->ResourceMakeCurrent()) {
     FML_DLOG(INFO) << "Could not make resource context current on IO thread. "
-                      "Async texture uploads "
-                      "will be disabled.";
+                      "Async texture uploads will be disabled. On Simulators, "
+                      "this is expected.";
     return nullptr;
   }