Remove experimental permission from infobars API and moving it to dev channel

chrome/browser/infobars/infobar_extension_apitest.cc

Index: chrome/browser/infobars/infobar_extension_apitest.cc
diff --git a/chrome/browser/infobars/infobar_extension_apitest.cc b/chrome/browser/infobars/infobar_extension_apitest.cc
index 1c7eb48382a87389f34032d5c087e676a7861ca1..5ca995e371beed0770566f3927fee5d5163e1f7f 100644
--- a/chrome/browser/infobars/infobar_extension_apitest.cc
+++ b/chrome/browser/infobars/infobar_extension_apitest.cc
@@ -15,9 +15,5 @@
 #endif
 
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, DISABLED_Infobars) {
-  // TODO(finnur): Remove once infobars are no longer experimental (bug 39511).
-  CommandLine::ForCurrentProcess()->AppendSwitch(
-      switches::kEnableExperimentalExtensionApis);
-
   ASSERT_TRUE(RunExtensionTest("infobars")) << message_;
 }