Disable ProfileChooserViewExtensionsTest.SigninButtonHasFocus

Flaky on Windows

TBR=tangltom@chromium.org

Bug: 855867
Change-Id: I32be5fa7473203dea8ab3dc25fbb9b5b68edd737
Reviewed-on: https://chromium-review.googlesource.com/1113087Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569968}

chrome/browser/ui/views/profiles/profile_chooser_view_browsertest.cc

@@ -271,7 +271,13 @@ class ProfileChooserViewExtensionsTest
   DISALLOW_COPY_AND_ASSIGN(ProfileChooserViewExtensionsTest);
 };
 
-IN_PROC_BROWSER_TEST_F(ProfileChooserViewExtensionsTest, SigninButtonHasFocus) {
+#if defined(OS_WIN)
+#define MAYBE_SigninButtonHasFocus DISABLED_SigninButtonHasFocus
+#else
+#define MAYBE_SigninButtonHasFocus SigninButtonHasFocus
+#endif
+IN_PROC_BROWSER_TEST_F(ProfileChooserViewExtensionsTest,
+                       MAYBE_SigninButtonHasFocus) {
   ASSERT_TRUE(profiles::IsMultipleProfilesEnabled());
   ASSERT_NO_FATAL_FAILURE(OpenProfileChooserView(browser()));