[CT] Split benchmarkArgs around one or more consecutive white spaces

ct/go/worker_scripts/run_chromium_perf_swarming/main.go

Index: ct/go/worker_scripts/run_chromium_perf_swarming/main.go
diff --git a/ct/go/worker_scripts/run_chromium_perf_swarming/main.go b/ct/go/worker_scripts/run_chromium_perf_swarming/main.go
index 6f62977613f3633d53f755c215c81eea1e670191..3eaaa8fc4a928db2e2dc33a6d11971d4b5494803 100644
--- a/ct/go/worker_scripts/run_chromium_perf_swarming/main.go
+++ b/ct/go/worker_scripts/run_chromium_perf_swarming/main.go
@@ -154,7 +154,7 @@ func runBenchmark(fileInfoName, pathToPagesets, localOutputDir, chromiumBuildNam
 	}
 	// Split benchmark args if not empty and append to args.
 	if *benchmarkExtraArgs != "" {
-		args = append(args, strings.Split(*benchmarkExtraArgs, " ")...)
+		args = append(args, strings.Fields(*benchmarkExtraArgs)...)
 	}
 	// Add the number of times to repeat.
 	args = append(args, fmt.Sprintf("--page-repeat=%d", *repeatBenchmark))