[Extensions] Update ExtensionSettingsUIBrowserTests to manifest v2

ExtensionSettingsUIBrowserTests have been updated to manifest v2.
Remove the allowance for manifest v1 extensions.

Bug: 816679

Change-Id: Ib0d7f277f7c2d79a941c689962e84030d24fe5b7
Reviewed-on: https://chromium-review.googlesource.com/1026086Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553381}

chrome/browser/ui/webui/extensions/extension_settings_browsertest.cc

@@ -24,7 +24,6 @@
 #include "content/public/test/browser_test_utils.h"
 #include "extensions/browser/extension_dialog_auto_confirm.h"
 #include "extensions/browser/extension_system.h"
-#include "extensions/common/switches.h"
 
 using extensions::Extension;
 using extensions::TestManagementPolicyProvider;
@@ -39,14 +38,6 @@ ExtensionSettingsUIBrowserTest::ExtensionSettingsUIBrowserTest()
 
 ExtensionSettingsUIBrowserTest::~ExtensionSettingsUIBrowserTest() {}
 
-void ExtensionSettingsUIBrowserTest::SetUpCommandLine(
-    base::CommandLine* command_line) {
-  WebUIBrowserTest::SetUpCommandLine(command_line);
-  // TODO(devlin): Remove this. See https://crbug.com/816679.
-  command_line->AppendSwitch(
-      extensions::switches::kAllowLegacyExtensionManifests);
-}
-
 void ExtensionSettingsUIBrowserTest::InstallGoodExtension() {
   EXPECT_TRUE(InstallExtension(test_data_dir_.AppendASCII("good.crx")));
 }

chrome/browser/ui/webui/extensions/extension_settings_browsertest.h

@@ -26,8 +26,6 @@ class ExtensionSettingsUIBrowserTest : public WebUIBrowserTest {
   ExtensionSettingsUIBrowserTest();
   ~ExtensionSettingsUIBrowserTest() override;
 
-  void SetUpCommandLine(base::CommandLine* command_line) override;
-
  protected:
   void InstallGoodExtension();