Don't synchronously flush when destroying RemoteImageBufferProxy

Reviewed by Said Abou-Hallawa.

No correctness tests added, since this should just be a performance improvement.

* WebProcess/GPU/graphics/RemoteImageBufferProxy.h:
(WebKit::RemoteImageBufferProxy::~RemoteImageBufferProxy):

Canonical link: https://commits.webkit.org/250662@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@294355 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebKit/WebProcess/GPU/graphics/RemoteImageBufferProxy.h

@@ -69,7 +69,7 @@ class RemoteImageBufferProxy : public WebCore::ConcreteImageBuffer<BackendType>
             return;
         }
 
-        flushDrawingContext();
+        flushDrawingContextAsync();
         m_remoteRenderingBackendProxy->remoteResourceCacheProxy().releaseImageBuffer(m_renderingResourceIdentifier);
     }