Enable extensions by default.

chrome/browser/extensions/extension_browsertest.cc

Index: chrome/browser/extensions/extension_browsertest.cc
diff --git a/chrome/browser/extensions/extension_browsertest.cc b/chrome/browser/extensions/extension_browsertest.cc
index cf7a5134a490249df7973b75727d498cd94058ec..9c14779b592b9687f1e14d2d0ef49ac958190d3e 100644
--- a/chrome/browser/extensions/extension_browsertest.cc
+++ b/chrome/browser/extensions/extension_browsertest.cc
@@ -39,8 +39,6 @@ void ExtensionBrowserTest::SetUpCommandLine(CommandLine* command_line) {
   // This enables it for extension hosts.
   ExtensionHost::EnableDOMAutomation();
 
-  command_line->AppendSwitch(switches::kEnableExtensions);
-
   PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir_);
   test_data_dir_ = test_data_dir_.AppendASCII("extensions");
 }