gdesktopappinfo.h not excluded on macOS

https://bugs.webkit.org/show_bug.cgi?id=248727

Reviewed by Carlos Garcia Campos.

Although macOS has most of the gio-unix-2.0 functionality, this
particular header is an exception and just needs to be handled
specially.

MacPorts has a patch to sometimes build with GDesktopAppInfo enabled, so
it's best to just detect the presence of the header instead of trying to
enable this code on OS(UNIX_BUT_NOT_MACOS_EXCEPT_SOMETIMES).

* Source/WTF/wtf/PlatformHave.h:
* Source/WebKit/UIProcess/Notifications/glib/NotificationService.cpp:
(WebKit::applicationIcon):

Canonical link: https://commits.webkit.org/258260@main

Source/WTF/wtf/PlatformHave.h

@@ -1382,3 +1382,9 @@
     || PLATFORM(APPLETV)
 #define HAVE_MEDIAPLAYBACKD 1
 #endif
+
+#if (PLATFORM(GTK) || PLATFORM(WPE)) && defined(__has_include)
+#if __has_include(<gio/gdesktopappinfo.h>)
+#define HAVE_GDESKTOPAPPINFO 1
+#endif
+#endif

Source/WebKit/UIProcess/Notifications/glib/NotificationService.cpp

@@ -31,7 +31,6 @@
 #include <WebCore/NotificationResources.h>
 #include <WebCore/RefPtrCairo.h>
 #include <cairo.h>
-#include <gio/gdesktopappinfo.h>
 #include <gio/gio.h>
 #include <glib/gi18n-lib.h>
 #include <mutex>
@@ -51,6 +50,10 @@
 #include <WebCore/GtkVersioning.h>
 #endif
 
+#if HAVE(GDESKTOPAPPINFO)
+#include <gio/gdesktopappinfo.h>
+#endif
+
 namespace WebKit {
 
 static const Seconds s_dbusCallTimeout = 20_ms;
@@ -294,6 +297,7 @@ void NotificationService::processCapabilities(GVariant* variant)
 static const char* applicationIcon(const char* applicationID)
 {
     static std::optional<CString> appIcon;
+#if HAVE(GDESKTOPAPPINFO)
     if (!appIcon) {
         appIcon = [applicationID]() -> CString {
             if (!applicationID)
@@ -328,6 +332,7 @@ static const char* applicationIcon(const char* applicationID)
             return { };
         }();
     }
+#endif // HAVE(GDESKTOPAPPINFO)
 
     return appIcon->data();
 }