Remove --extra-chrome-flags command line switch.

chrome/test/base/test_switches.cc

Index: chrome/test/base/test_switches.cc
diff --git a/chrome/test/base/test_switches.cc b/chrome/test/base/test_switches.cc
index 1316d3582faa51df0be42ae7f1ae1a502544fc59..86d498870b053d53935b43c9d92ebb611bd0d6fa 100644
--- a/chrome/test/base/test_switches.cc
+++ b/chrome/test/base/test_switches.cc
@@ -9,9 +9,6 @@ namespace switches {
 // Also emit full event trace logs for successful tests.
 const char kAlsoEmitSuccessLogs[] = "also-emit-success-logs";
 
-// Extra flags that the test should pass to launched browser process.
-const char kExtraChromeFlags[] = "extra-chrome-flags";
-
 // Enable Chromium branding of the executable.
 const char kEnableChromiumBranding[] = "enable-chromium-branding";