[GStreamer] Avoid using decoding limits for all configurations

https://bugs.webkit.org/show_bug.cgi?id=264941

Reviewed by Philippe Normand.

When VIDEO_DECODING_LIMIT support is enabled, after a first call of
isContentTypeSupported() with Configuration::Decoding, the video
limits are remembered in a static variable.

They were then used for all subsequent isContentTypeSupported() calls,
regardless of the configuration.

This should be limited to Configuration::Decoding.

* Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.cpp:
(WebCore::GStreamerRegistryScanner::isContentTypeSupported const):

Canonical link: https://commits.webkit.org/270877@main

Author: blino

Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.cpp

@@ -757,18 +757,21 @@ bool GStreamerRegistryScanner::supportsFeatures(const String& features) const
 
 MediaPlayerEnums::SupportsType GStreamerRegistryScanner::isContentTypeSupported(Configuration configuration, const ContentType& contentType, const Vector<ContentType>& contentTypesRequiringHardwareSupport) const
 {
-    static std::optional<VideoDecodingLimits> videoDecodingLimits;
+    VideoDecodingLimits* videoDecodingLimits = nullptr;
 #ifdef VIDEO_DECODING_LIMIT
+    static std::optional<VideoDecodingLimits> videoDecodingLimitsDefaults;
     static std::once_flag onceFlag;
     if (configuration == Configuration::Decoding) {
         std::call_once(onceFlag, [] {
-            videoDecodingLimits = videoDecoderLimitsDefaults();
-            if (!videoDecodingLimits) {
+            videoDecodingLimitsDefaults = videoDecoderLimitsDefaults();
+            if (!videoDecodingLimitsDefaults) {
                 GST_WARNING("Parsing VIDEO_DECODING_LIMIT failed");
                 ASSERT_NOT_REACHED();
                 return;
             }
         });
+        if (videoDecodingLimitsDefaults)
+            videoDecodingLimits = &*videoDecodingLimitsDefaults;
     }
 #endif