Enable Linux-only OmniboxViewViewsTest.SelectionClipboard

This test seems to work as-is, and passed 100 times in a row locally.
Hopefully it's no longer flaky; let's give it a shot.

Bug: 676746
Change-Id: I28857f2c97b354160bd945bb284083b080938899
Reviewed-on: https://chromium-review.googlesource.com/922794Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537329}

chrome/browser/ui/views/omnibox/omnibox_view_views_browsertest.cc

@@ -216,8 +216,7 @@ IN_PROC_BROWSER_TEST_F(OmniboxViewViewsTest, SelectAllOnClick) {
 }
 
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
-// TODO(crbug.com/676746): Fix and re-enable this test.
-IN_PROC_BROWSER_TEST_F(OmniboxViewViewsTest, DISABLED_SelectionClipboard) {
+IN_PROC_BROWSER_TEST_F(OmniboxViewViewsTest, SelectionClipboard) {
   OmniboxView* omnibox_view = NULL;
   ASSERT_NO_FATAL_FAILURE(GetOmniboxViewForBrowser(browser(), &omnibox_view));
   omnibox_view->SetUserText(base::ASCIIToUTF16("http://www.google.com/"));