Handle the case where an extension could be unloaded after compiling …

…DNR rules

https://bugs.webkit.org/show_bug.cgi?id=271493
rdar://123900589

Reviewed by Timothy Hatcher.

If the extension has been unloaded, iterating the user content controllers will lead to a crash.

* Source/WebKit/UIProcess/Extensions/Cocoa/WebExtensionContextCocoa.mm:
(WebKit::WebExtensionContext::addDeclarativeNetRequestRulesToPrivateUserContentControllers):
(WebKit::WebExtensionContext::compileDeclarativeNetRequestRules):

Canonical link: https://commits.webkit.org/276578@main

Source/WebKit/UIProcess/Extensions/Cocoa/WebExtensionContextCocoa.mm

@@ -4114,6 +4114,10 @@ void effectiveAppearanceDidChange(Inspector::ExtensionAppearance appearance) ove
         if (!ruleList)
             return;
 
+        // The extension could have been unloaded before this was called.
+        if (!isLoaded())
+            return;
+
         for (auto& controller : extensionController()->allPrivateUserContentControllers())
             controller.addContentRuleList(*ruleList, m_baseURL);
     });
@@ -4159,6 +4163,12 @@ void effectiveAppearanceDidChange(Inspector::ExtensionAppearance appearance) ove
 
         dispatch_async(dispatch_get_main_queue(), makeBlockPtr([this, protectedThis = Ref { *this }, completionHandler = WTFMove(completionHandler), previouslyLoadedHash = String { previouslyLoadedHash }, hashOfWebKitRules = String { hashOfWebKitRules }, webKitRules = String { webKitRules }]() mutable {
             API::ContentRuleListStore::defaultStore().lookupContentRuleListFile(declarativeNetRequestContentRuleListFilePath(), uniqueIdentifier().isolatedCopy(), [this, protectedThis = Ref { *this }, completionHandler = WTFMove(completionHandler), previouslyLoadedHash, hashOfWebKitRules, webKitRules](RefPtr<API::ContentRuleList> foundRuleList, std::error_code) mutable {
+                // The extension could have been unloaded before this was called.
+                if (!isLoaded()) {
+                    completionHandler(false);
+                    return;
+                }
+
                 if (foundRuleList) {
                     if ([previouslyLoadedHash isEqualToString:hashOfWebKitRules]) {
                         for (auto& userContentController : userContentControllers())
@@ -4176,6 +4186,12 @@ void effectiveAppearanceDidChange(Inspector::ExtensionAppearance appearance) ove
                         return;
                     }
 
+                    // The extension could have been unloaded before this was called.
+                    if (!isLoaded()) {
+                        completionHandler(false);
+                        return;
+                    }
+
                     [m_state setObject:hashOfWebKitRules forKey:lastLoadedDeclarativeNetRequestHashStateKey];
                     writeStateToStorage();