Convert WindowOpenDisposition to an enum class.

This is done in preparation for mojoifying this enum; mojo only generates 'enum class' enums.

[email protected]
BUG=627852
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2248873002
Cr-Commit-Position: refs/heads/master@{#415722}
diff --git a/chrome/browser/web_bluetooth_browsertest.cc b/chrome/browser/web_bluetooth_browsertest.cc
index 98feac5..5bbec68 100644
--- a/chrome/browser/web_bluetooth_browsertest.cc
+++ b/chrome/browser/web_bluetooth_browsertest.cc
@@ -78,7 +78,7 @@
   crash_observer.Wait();
 
   // Reload tab.
-  chrome::Reload(browser(), CURRENT_TAB);
+  chrome::Reload(browser(), WindowOpenDisposition::CURRENT_TAB);
   content::WaitForLoadStop(
       browser()->tab_strip_model()->GetActiveWebContents());