Tentatively re-land flaky test: #WindowClientReady

Context:
PaymentRequestEvent.openWindow() fails with a cross-origin error
caused by some unknown factors.

Change:
* Reverted the reverting CL: crrev.com/c/2220705

Bug: 1075481

Change-Id: I2a3452f58d5686e0dcfcd1ba0e30229e69bfe280
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459389Reviewed-by: Sahel Sharify <sahel@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818151}

chrome/browser/payments/expandable_payment_handler_browsertest.cc

@@ -3,18 +3,11 @@
 // found in the LICENSE file.
 
 #include "base/test/scoped_feature_list.h"
-#include "build/build_config.h"
 #include "chrome/test/payments/payment_request_platform_browsertest_base.h"
 #include "components/payments/content/android/payment_feature_list.h"
 #include "content/public/test/browser_test.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 
-#if defined(OS_ANDROID)
-#define DISABLE_ON_ANDROID(test_name) DISABLED_##test_name
-#else
-#define DISABLE_ON_ANDROID(test_name) test_name
-#endif
-
 namespace payments {
 namespace {
 
@@ -120,9 +113,7 @@ IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest,
 }
 
 // Make sure openWindow() can be resolved into window client.
-// Android: Flaky. See https://crbug.com/1075481.
-IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest,
-                       DISABLE_ON_ANDROID(WindowClientReady)) {
+IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest, WindowClientReady) {
   std::string expected = "success";
   EXPECT_EQ(expected, content::EvalJs(GetActiveWebContents(), "install()"));
   EXPECT_EQ("app_is_ready",