Re-enable FocusRestore/FocusRestoreOnTabSwitch in FindInPageTest for Linux_AURA

Changes:
Because now ui_test_utils::BringBrowserWindowToFront now supports activation waiter, let us reopen these tests for Linux_aura.

BUG=163931
TEST=automated tests

Review-Url: https://codereview.chromium.org/2600473003
Cr-Commit-Position: refs/heads/master@{#441291}

chrome/browser/ui/views/find_bar_views_interactive_uitest.cc

@@ -227,15 +227,7 @@ IN_PROC_BROWSER_TEST_F(FindInPageTest, ButtonsDisabledWithoutText) {
   EXPECT_TRUE(IsViewFocused(browser(), VIEW_ID_FIND_IN_PAGE_CLOSE_BUTTON));
 }
 
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS) && defined(USE_AURA)
-// TODO(erg): linux_aura bringup: http://crbug.com/163931
-#define MAYBE_FocusRestore DISABLED_FocusRestore
-#else
-#define MAYBE_FocusRestore FocusRestore
-#endif
-
-// Flaky because the test server fails to start? See: http://crbug.com/96594.
-IN_PROC_BROWSER_TEST_F(FindInPageTest, MAYBE_FocusRestore) {
+IN_PROC_BROWSER_TEST_F(FindInPageTest, FocusRestore) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url = embedded_test_server()->GetURL("/title1.html");
@@ -351,15 +343,7 @@ IN_PROC_BROWSER_TEST_F(FindInPageTest, DISABLED_SelectionRestoreOnTabSwitch) {
   EXPECT_EQ(ASCIIToUTF16("de"), GetFindBarSelectedText());
 }
 
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS) && defined(USE_AURA)
-// TODO(erg): linux_aura bringup: http://crbug.com/163931
-#define MAYBE_FocusRestoreOnTabSwitch DISABLED_FocusRestoreOnTabSwitch
-#else
-#define MAYBE_FocusRestoreOnTabSwitch FocusRestoreOnTabSwitch
-#endif
-
-// Flaky because the test server fails to start? See: http://crbug.com/96594.
-IN_PROC_BROWSER_TEST_F(FindInPageTest, MAYBE_FocusRestoreOnTabSwitch) {
+IN_PROC_BROWSER_TEST_F(FindInPageTest, FocusRestoreOnTabSwitch) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   // First we navigate to our test page (tab A).