[CT] Add desktop device when running run_benchmark

ct/go/worker_scripts/run_chromium_perf/main.go

 // run_chromium_perf is an application that runs the specified benchmark over CT's
 // webpage archives.
 package main
 
 import (
         "bytes"
         "encoding/csv"
         "flag"
         "fmt"
         "io/ioutil"
@@ skipping 287 matching lines @@
                 benchmark,
                 "--also-run-disabled-tests",
                 "--user-agent=" + decodedPageset.UserAgent,
                 "--urls-list=" + decodedPageset.UrlsList,
                 "--archive-data-file=" + decodedPageset.ArchiveDataFile,
         }
 
         // Need to capture output for all benchmarks.
         outputDirArgValue := filepath.Join(localOutputDir, pagesetName)
         args = append(args, "--output-dir="+outputDirArgValue)
-        // Figure out which browser should be used.
+        // Figure out which browser and device should be used.
         if *targetPlatform == util.PLATFORM_ANDROID {
                 if err := util.InstallChromeAPK(chromiumBuildName); err != nil {
                         return fmt.Errorf("Error while installing APK: %s", err)
                 }
                 args = append(args, "--browser=android-chromium")
         } else {
                 args = append(args, "--browser=exact", "--browser-executable="+chromiumBinary)
+                args = append(args, "--device=desktop")
         }
         // Split benchmark args if not empty and append to args.
         if *benchmarkExtraArgs != "" {
-                for _, benchmarkArg := range strings.Fields(*benchmarkExtraArgs) {
-                        args = append(args, benchmarkArg)
-                }
+                args = append(args, strings.Fields(*benchmarkExtraArgs)...)
         }
         // Add the number of times to repeat.
         args = append(args, fmt.Sprintf("--page-repeat=%d", *repeatBenchmark))
         // Add browserArgs if not empty to args.
         if browserExtraArgs != "" {
                 args = append(args, "--extra-browser-args="+browserExtraArgs)
         }
         // Set the PYTHONPATH to the pagesets and the telemetry dirs.
         env := []string{
                 fmt.Sprintf("PYTHONPATH=%s:%s:%s:%s:$PYTHONPATH", pathToPagesets, util.TelemetryBinariesDir, util.TelemetrySrcDir, util.CatapultSrcDir),
@@ skipping 93 matching lines @@
                 return fmt.Errorf("Could not write to %s: %s", csvPath, err)
         }
         // Write all values.
         for _, row := range values {
                 if err := writer.Write(row); err != nil {
                         return fmt.Errorf("Could not write to %s: %s", csvPath, err)
                 }
         }
         return nil
 }