Fix GCC build for target 'all'

chrome/browser/media/cast_remoting_connector_fuzzertest.cc

Index: chrome/browser/media/cast_remoting_connector_fuzzertest.cc
diff --git a/chrome/browser/media/cast_remoting_connector_fuzzertest.cc b/chrome/browser/media/cast_remoting_connector_fuzzertest.cc
index 87191007e3596ee355a7543fd434460a333f934e..d43cf95c874b9322310c58599685884065a0a082 100644
--- a/chrome/browser/media/cast_remoting_connector_fuzzertest.cc
+++ b/chrome/browser/media/cast_remoting_connector_fuzzertest.cc
@@ -15,6 +15,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   // Make sure the compiler does not try to optimize-away calls by storing their
   // results in a volatile variable.
   volatile unsigned int ignored_result;
+  (void)ignored_result;
 
   using Messaging = CastRemotingConnectorMessaging;