[Extensions] Update PageActionCrash25562 test to manifest v2

The PageActionCrash25562 test has been updated to manifest v2.
Remove the allowance for manifest v1 extensions.

Bug: 816679
Change-Id: I56c954aebb48a469cd7a9ab5c9f916d73498d5d5
Reviewed-on: https://chromium-review.googlesource.com/1018408
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552145}

chrome/browser/extensions/page_action_browsertest.cc

@@ -36,9 +36,6 @@ const std::string kHashPageB =
 IN_PROC_BROWSER_TEST_F(ExtensionBrowserTest, PageActionCrash25562) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(
-      switches::kAllowLegacyExtensionManifests);
-
   // This page action will not show an icon, since it doesn't specify one but
   // is included here to test for a crash (http://crbug.com/25562).
   ASSERT_TRUE(LoadExtension(