Control TaskScheduler initialization params in renderers via field trial.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 0d4b017bf7bdf809b335ed9a5d2ef6a36ad3342a..b3c6215cdb924b1a0375986321e5e34fc7a1bd28 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -145,6 +145,7 @@
 #include "components/spellcheck/spellcheck_build_features.h"
 #include "components/startup_metric_utils/browser/startup_metric_host_impl.h"
 #include "components/task_scheduler_util/browser/initialization.h"
+#include "components/task_scheduler_util/common/variations_util.h"
 #include "components/translate/core/common/translate_switches.h"
 #include "components/url_formatter/url_fixer.h"
 #include "components/variations/variations_associated_data.h"
@@ -1817,6 +1818,15 @@ void ChromeContentBrowserClient::AppendExtraCommandLineSwitches(
   StackSamplingConfiguration::Get()->AppendCommandLineSwitchForChildProcess(
       process_type,
       command_line);
+
+  if (process_type == switches::kRendererProcess) {
+    std::map<std::string, std::string> task_scheduler_variation_params;
+    if (variations::GetVariationParams("BrowserScheduler",
+                                       &task_scheduler_variation_params)) {
+      task_scheduler_util::AddVariationParamsToCommandLine(
+          task_scheduler_variation_params, "Renderer", command_line);
+    }
+  }
 }
 
 std::string ChromeContentBrowserClient::GetApplicationLocale() {