Correctly annotate availability for universal link support.

BUG=1044828

Change-Id: Idd5a5f4fed6ca3d7a9bcae0a14b130e4c6ce9022
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2020182
Auto-Submit: Avi Drissman <avi@chromium.org>
Reviewed-by: Leonard Grey <lgrey@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735053}

chrome/browser/apps/intent_helper/mac_apps_navigation_throttle.mm

@@ -46,11 +46,9 @@ IntentPickerAppInfo AppInfoForAppUrl(NSURL* app_url) {
 // TODO(avi): When we move to the 10.15 SDK, use correct weak-linking of this
 // framework rather than dlopen(), and correct @available syntax to access this
 // class.
-SFUniversalLink* GetUniversalLink(const GURL& url) {
+SFUniversalLink* API_AVAILABLE(macos(10.15)) GetUniversalLink(const GURL& url) {
   static void* safari_services = []() -> void* {
-    if (@available(macOS 10.15, *))
     return dlopen(kSafariServicesFrameworkPath, RTLD_LAZY);
-    return nullptr;
   }();
 
   static const Class SFUniversalLink_class =
@@ -64,9 +62,11 @@ SFUniversalLink* GetUniversalLink(const GURL& url) {
 }
 
 base::Optional<IntentPickerAppInfo> AppInfoForUrl(const GURL& url) {
+  if (@available(macOS 10.15, *)) {
     SFUniversalLink* link = GetUniversalLink(url);
     if (link)
       return AppInfoForAppUrl(link.applicationURL);
+  }
 
   return base::nullopt;
 }