[Prerender] Add a "SimpleLoad" mode to be used as a comparison reference

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 19fc161da154168457c504230d5fe9d46a13af99..ae359f75bcc85f7f33b389bf702869ca13016d7e 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -755,6 +755,9 @@ const char kPrerenderModeSwitchValueDisabled[] = "disabled";
 const char kPrerenderModeSwitchValueEnabled[] = "enabled";
 //   prefetch: NoState Prefetch experiment.
 const char kPrerenderModeSwitchValuePrefetch[] = "prefetch";
+//   simple-load: experiment with prerendering disabled but metrics reporting
+//                enabled, to use as a reference for comparisons.
+const char kPrerenderModeSwitchValueSimpleLoad[] = "simple-load";
 
 // Use IPv6 only for privet HTTP.
 const char kPrivetIPv6Only[]                   = "privet-ipv6-only";