[iOS] Reenable testXClientData

This CL re-enable testXClientData as it was probably failing because of
a DCHECK in WebController, that should have been fixed in
crrev.com/c/1992063.

Fixed: 1036225
Change-Id: Id9a85c0f35310e79adcf030d222cce2e9e36274b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1993813
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731180}

ios/chrome/browser/ui/omnibox/omnibox_egtest.mm

@@ -150,8 +150,7 @@ id<GREYMatcher> SearchCopiedTextButton() {
 
 // Tests that the XClientData header is sent when navigating to
 // https://google.com through the omnibox.
-// TODO(crbug.com/1036225): Test very flaky on all config.
-- (void)DISABLED_testXClientData {
+- (void)testXClientData {
   // Rewrite the google URL to localhost URL.
   [OmniboxAppInterface rewriteGoogleURLToLocalhost];