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/extensions/process_management_browsertest.cc b/chrome/browser/extensions/process_management_browsertest.cc
index f8b3777..5d4facc 100644
--- a/chrome/browser/extensions/process_management_browsertest.cc
+++ b/chrome/browser/extensions/process_management_browsertest.cc
@@ -84,31 +84,39 @@
       browser(), base_url.Resolve("isolated_apps/app1/main.html"));
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), GURL(chrome::kChromeUINewTabURL),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("hosted_app/main.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("test_file.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
 
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("isolated_apps/app2/main.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), GURL(chrome::kChromeUINewTabURL),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("api_test/app_process/path1/empty.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("test_file_with_body.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
 
   // Load another copy of isolated app 1.
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), base_url.Resolve("isolated_apps/app1/main.html"),
-      NEW_FOREGROUND_TAB, ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
 
   // Load another extension.
   const extensions::Extension* extension2 = LoadExtension(