Drop enable_shared_from_this from RCTImageResponseObserverProxy

Review feedback: the address comparison in RCTImageComponentView is
enough on its own. The new proxy is allocated before the previous one is
released, so consecutive subscriptions never share an address. Reuse is
only possible after two resubscriptions while a callback from the first
one is still queued.

This leaves RCTImageResponseObserverProxy and the C++ API snapshots
unchanged.

Author: mattijsf

packages/react-native/React/Fabric/Mounting/ComponentViews/Image/RCTImageComponentView.mm

@@ -124,6 +124,8 @@ - (void)_setStateAndResubscribeImageResponseObserver:(const ImageShadowNode::Con
   if (_state) {
     // A new observer per subscription: callbacks of a previous request can still be queued on the
     // main queue (e.g. after this view was recycled and reused), and must not be applied here.
+    // The callbacks are matched by the proxy's address. The new proxy is allocated before the
+    // previous one is released, so two consecutive subscriptions never share an address.
     _imageResponseObserverProxy = std::make_shared<RCTImageResponseObserverProxy>(self);
     auto &observerCoordinator = _state->getData().getImageRequest().getObserverCoordinator();
     observerCoordinator.addObserver(_imageResponseObserverProxy);

packages/react-native/React/Fabric/RCTImageResponseObserverProxy.h

@@ -11,16 +11,11 @@
 
 #include <react/renderer/imagemanager/ImageResponseObserver.h>
 
-#include <memory>
-
 NS_ASSUME_NONNULL_BEGIN
 
 namespace facebook::react {
 
-// Must be owned by a std::shared_ptr: callbacks queued to the main queue keep the
-// proxy alive, so its address can identify the subscription they belong to.
-class RCTImageResponseObserverProxy final : public ImageResponseObserver,
-                                            public std::enable_shared_from_this<RCTImageResponseObserverProxy> {
+class RCTImageResponseObserverProxy final : public ImageResponseObserver {
  public:
   RCTImageResponseObserverProxy(id<RCTImageResponseDelegate> delegate = nil);
 

packages/react-native/React/Fabric/RCTImageResponseObserverProxy.mm

@@ -24,28 +24,28 @@
   UIImage *image = (UIImage *)unwrapManagedObject(imageResponse.getImage());
   id metadata = unwrapManagedObject(imageResponse.getMetadata());
   id<RCTImageResponseDelegate> delegate = delegate_;
-  auto strongThis = shared_from_this();
+  auto this_ = this;
   RCTExecuteOnMainQueue(^{
-    [delegate didReceiveImage:image metadata:metadata fromObserver:strongThis.get()];
+    [delegate didReceiveImage:image metadata:metadata fromObserver:this_];
   });
 }
 
 void RCTImageResponseObserverProxy::didReceiveProgress(float progress, int64_t loaded, int64_t total) const
 {
-  auto strongThis = shared_from_this();
+  auto this_ = this;
   id<RCTImageResponseDelegate> delegate = delegate_;
   RCTExecuteOnMainQueue(^{
-    [delegate didReceiveProgress:progress loaded:loaded total:total fromObserver:strongThis.get()];
+    [delegate didReceiveProgress:progress loaded:loaded total:total fromObserver:this_];
   });
 }
 
 void RCTImageResponseObserverProxy::didReceiveFailure(const ImageLoadError &errorResponse) const
 {
-  auto strongThis = shared_from_this();
+  auto this_ = this;
   NSError *error = (NSError *)unwrapManagedObject(errorResponse.getError());
   id<RCTImageResponseDelegate> delegate = delegate_;
   RCTExecuteOnMainQueue(^{
-    [delegate didReceiveFailure:error fromObserver:strongThis.get()];
+    [delegate didReceiveFailure:error fromObserver:this_];
   });
 }
 

scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api

@@ -6396,7 +6396,7 @@ class facebook::react::RCTHermesInstance : public facebook::react::JSRuntimeFact
   public ~RCTHermesInstance() override;
 }
 
-class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver, public std::enable_shared_from_this<facebook::react::RCTImageResponseObserverProxy> {
+class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver {
   public RCTImageResponseObserverProxy(id<RCTImageResponseDelegate> delegate = nil);
   public virtual void didReceiveFailure(const facebook::react::ImageLoadError& error) const override;
   public virtual void didReceiveImage(const facebook::react::ImageResponse& imageResponse) const override;

scripts/cxx-api/api-snapshots/ReactAppleNewarchCxx.api

@@ -6272,7 +6272,7 @@ class facebook::react::RCTHermesInstance : public facebook::react::JSRuntimeFact
   public ~RCTHermesInstance() override;
 }
 
-class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver, public std::enable_shared_from_this<facebook::react::RCTImageResponseObserverProxy> {
+class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver {
   public RCTImageResponseObserverProxy(id<RCTImageResponseDelegate> delegate = nil);
   public virtual void didReceiveFailure(const facebook::react::ImageLoadError& error) const override;
   public virtual void didReceiveImage(const facebook::react::ImageResponse& imageResponse) const override;

scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api

@@ -6393,7 +6393,7 @@ class facebook::react::RCTHermesInstance : public facebook::react::JSRuntimeFact
   public ~RCTHermesInstance() override;
 }
 
-class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver, public std::enable_shared_from_this<facebook::react::RCTImageResponseObserverProxy> {
+class facebook::react::RCTImageResponseObserverProxy : public facebook::react::ImageResponseObserver {
   public RCTImageResponseObserverProxy(id<RCTImageResponseDelegate> delegate = nil);
   public virtual void didReceiveFailure(const facebook::react::ImageLoadError& error) const override;
   public virtual void didReceiveImage(const facebook::react::ImageResponse& imageResponse) const override;