Revert "Tentatively re-land flaky test: #WindowClientReady"

This reverts commit ece73b5c.

Reason for revert: the test is still flaky.

Original change's description:
> 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/+/2459389
> Reviewed-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}

TBR=yfriedman@chromium.org,sahel@chromium.org,maxlg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1075481
Change-Id: I423ff1c7cffe050e8b15267ee7e7e522cb138fa5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2511330Reviewed-by: Liquan (Max) Gu <maxlg@chromium.org>
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822843}

chrome/browser/payments/expandable_payment_handler_browsertest.cc

@@ -3,11 +3,18 @@
 // 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 {
 
@@ -113,7 +120,9 @@ IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest,
 }
 
 // Make sure openWindow() can be resolved into window client.
-IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest, WindowClientReady) {
+// Android: Flaky. See https://crbug.com/1075481.
+IN_PROC_BROWSER_TEST_F(ExpandablePaymentHandlerBrowserTest,
+                       DISABLE_ON_ANDROID(WindowClientReady)) {
   std::string expected = "success";
   EXPECT_EQ(expected, content::EvalJs(GetActiveWebContents(), "install()"));
   EXPECT_EQ("app_is_ready",