Remove incorrect const constraint from UIManager commit hooks

Summary:
The `const` modified in UIManagerCommitHook prevents us from mutating the commit hook itself (which doesn't make any sense as commit hooks might want to update their internal state as response to new commits).

This removes the constraint so we can remove the `const` modifier from `MutationObserverManager` in D46149086.

Changelog: [internal]

Reviewed By: sammy-SC

Differential Revision: D46149085

fbshipit-source-id: e84c765535437a9877c2c53b1857b2be91c0db3e

Author: rubennorte

packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.cpp

@@ -114,7 +114,7 @@ Scheduler::Scheduler(
   commitHooks_ = schedulerToolbox.commitHooks;
   uiManager_ = uiManager;
 
-  for (auto const &commitHook : commitHooks_) {
+  for (auto &commitHook : commitHooks_) {
     uiManager->registerCommitHook(*commitHook);
   }
 
@@ -147,7 +147,7 @@ Scheduler::~Scheduler() {
   LOG(WARNING) << "Scheduler::~Scheduler() was called (address: " << this
                << ").";
 
-  for (auto const &commitHook : commitHooks_) {
+  for (auto &commitHook : commitHooks_) {
     uiManager_->unregisterCommitHook(*commitHook);
   }
 

packages/react-native/ReactCommon/react/renderer/scheduler/Scheduler.h

@@ -124,7 +124,7 @@ class Scheduler final : public UIManagerDelegate {
   std::shared_ptr<UIManager> uiManager_;
   std::shared_ptr<const ReactNativeConfig> reactNativeConfig_;
 
-  std::vector<std::shared_ptr<UIManagerCommitHook const>> commitHooks_;
+  std::vector<std::shared_ptr<UIManagerCommitHook>> commitHooks_;
 
   /*
    * At some point, we have to have an owning shared pointer to something that

packages/react-native/ReactCommon/react/renderer/scheduler/SchedulerToolbox.h

@@ -75,7 +75,7 @@ struct SchedulerToolbox final {
   /*
    * A list of `UIManagerCommitHook`s that should be registered in `UIManager`.
    */
-  std::vector<std::shared_ptr<UIManagerCommitHook const>> commitHooks;
+  std::vector<std::shared_ptr<UIManagerCommitHook>> commitHooks;
 };
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp

@@ -594,8 +594,7 @@ ShadowTreeRegistry const &UIManager::getShadowTreeRegistry() const {
   return shadowTreeRegistry_;
 }
 
-void UIManager::registerCommitHook(
-    UIManagerCommitHook const &commitHook) const {
+void UIManager::registerCommitHook(UIManagerCommitHook &commitHook) {
   std::unique_lock lock(commitHookMutex_);
   react_native_assert(
       std::find(commitHooks_.begin(), commitHooks_.end(), &commitHook) ==
@@ -604,8 +603,7 @@ void UIManager::registerCommitHook(
   commitHooks_.push_back(&commitHook);
 }
 
-void UIManager::unregisterCommitHook(
-    UIManagerCommitHook const &commitHook) const {
+void UIManager::unregisterCommitHook(UIManagerCommitHook &commitHook) {
   std::unique_lock lock(commitHookMutex_);
   auto iterator =
       std::find(commitHooks_.begin(), commitHooks_.end(), &commitHook);
@@ -638,7 +636,7 @@ RootShadowNode::Unshared UIManager::shadowTreeWillCommit(
   std::shared_lock lock(commitHookMutex_);
 
   auto resultRootShadowNode = newRootShadowNode;
-  for (auto const *commitHook : commitHooks_) {
+  for (auto *commitHook : commitHooks_) {
     resultRootShadowNode = commitHook->shadowTreeWillCommit(
         shadowTree, oldRootShadowNode, resultRootShadowNode);
   }

packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.h

@@ -80,8 +80,8 @@ class UIManager final : public ShadowTreeDelegate {
   /*
    * Registers and unregisters a commit hook.
    */
-  void registerCommitHook(UIManagerCommitHook const &commitHook) const;
-  void unregisterCommitHook(UIManagerCommitHook const &commitHook) const;
+  void registerCommitHook(UIManagerCommitHook &commitHook);
+  void unregisterCommitHook(UIManagerCommitHook &commitHook);
 
   /*
    * Registers and unregisters a mount hook.
@@ -224,7 +224,7 @@ class UIManager final : public ShadowTreeDelegate {
   ContextContainer::Shared contextContainer_;
 
   mutable std::shared_mutex commitHookMutex_;
-  mutable std::vector<UIManagerCommitHook const *> commitHooks_;
+  mutable std::vector<UIManagerCommitHook *> commitHooks_;
 
   mutable std::shared_mutex mountHookMutex_;
   mutable std::vector<UIManagerMountHook *> mountHooks_;

packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerCommitHook.h

@@ -22,10 +22,9 @@ class UIManagerCommitHook {
   /*
    * Called right after the commit hook is registered or unregistered.
    */
-  virtual void commitHookWasRegistered(
-      UIManager const &uiManager) const noexcept = 0;
+  virtual void commitHookWasRegistered(UIManager const &uiManager) noexcept = 0;
   virtual void commitHookWasUnregistered(
-      UIManager const &uiManager) const noexcept = 0;
+      UIManager const &uiManager) noexcept = 0;
 
   /*
    * Called right before a `ShadowTree` commits a new tree.
@@ -35,7 +34,7 @@ class UIManagerCommitHook {
   virtual RootShadowNode::Unshared shadowTreeWillCommit(
       ShadowTree const &shadowTree,
       RootShadowNode::Shared const &oldRootShadowNode,
-      RootShadowNode::Unshared const &newRootShadowNode) const noexcept = 0;
+      RootShadowNode::Unshared const &newRootShadowNode) noexcept = 0;
 
   virtual ~UIManagerCommitHook() noexcept = default;
 };