Add an infobar if a session is being controlled by an automated test.

chrome/browser/extensions/extension_service.cc

Index: chrome/browser/extensions/extension_service.cc
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 748fb3e5ded1599ea1da1ef12b6647c5fb88e90a..3c7d9c2196580d740b2bcbfbae670b8967c01d20 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -69,6 +69,7 @@
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/storage_partition.h"
+#include "content/public/common/content_switches.h"
 #include "extensions/browser/app_sorting.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_host.h"
@@ -439,6 +440,12 @@ void ExtensionService::Init() {
   LoadExtensionsFromCommandLineFlag(switches::kDisableExtensionsExcept);
   if (extensions_enabled_)
     LoadExtensionsFromCommandLineFlag(switches::kLoadExtension);
+  // TODO(samuong): Remove this when ChromeDriver stops supporting Chrome 56.
+  // ChromeDriver has no way of determining the Chrome version until after
+  // launch, so it needs to continue passing load-component-extension until it
+  // stops supporting Chrome 56.
+  if (command_line_->HasSwitch(switches::kEnableChromeDriver))
+    LoadExtensionsFromCommandLineFlag(switches::kLoadComponentExtension);

[Devlin, 2017/02/01 23:05:00]

I think we should make this a separate change - let's have this one only target
the infobar.

[samuong, 2017/02/04 00:11:03]

Done.

   EnabledReloadableExtensions();
   MaybeFinishShutdownDelayed();
   SetReadyAndNotifyListeners();