[Payments] Have an observer for canMakePayment, for testing.

chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <vector>
 
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/views/payments/payment_request_browsertest_base.h"
 #include "components/autofill/core/browser/autofill_test_utils.h"
 #include "components/autofill/core/browser/credit_card.h"
 #include "content/public/test/browser_test_utils.h"
 
 namespace payments {
 
 class PaymentRequestCanMakePaymentQueryTest
     : public PaymentRequestBrowserTestBase {
  protected:
   PaymentRequestCanMakePaymentQueryTest()
       : PaymentRequestBrowserTestBase(
             "/payment_request_can_make_payment_query_test.html") {}
 
   void CallCanMakePayment() {
+    ResetEventObserver(DialogEvent::CAN_MAKE_PAYMENT_CALLED);
     ASSERT_TRUE(content::ExecuteScript(GetActiveWebContents(), "buy();"));
+    WaitForObservedEvent();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestCanMakePaymentQueryTest);
 };
 
 // Visa is required, and user has a visa instrument.
-// Test is flaky. crbug.com/705225
 IN_PROC_BROWSER_TEST_F(PaymentRequestCanMakePaymentQueryTest,
-                       DISABLED_CanMakePayment_Supported) {
+                       CanMakePayment_Supported) {
   const autofill::CreditCard card = autofill::test::GetCreditCard();  // Visa.
   AddCreditCard(card);
 
   CallCanMakePayment();
 
   ExpectBodyContains(std::vector<base::string16>{base::ASCIIToUTF16("true")});
 }
 
 // Visa is required, and user has a visa instrument, and user is in incognito
 // mode.
@@ skipping 15 matching lines @@
   const autofill::CreditCard card = autofill::test::GetCreditCard2();  // Amex.
   AddCreditCard(card);
 
   CallCanMakePayment();
 
   ExpectBodyContains(std::vector<base::string16>{base::ASCIIToUTF16("false")});
 }
 
 // Visa is required, and user doesn't have a visa instrument and the user is in
 // incognito mode.
-// Test is flaky. crbug.com/705271
 IN_PROC_BROWSER_TEST_F(PaymentRequestCanMakePaymentQueryTest,
-                       DISABLED_CanMakePayment_NotSupported_Incognito) {
+                       CanMakePayment_NotSupported_Incognito) {

[please use gerrit instead, 2017/03/27 18:12:32]

NotSupported seems like the wrong phrase. Should it be AlwaysTrue instead?

[Mathieu, 2017/03/27 18:28:24]

It's the name of the test case. We are calling CanMakePayment, payment is
NotSupported, and we are in Incognito.

I've added a description as to what is the test expectation.

   SetIncognitoForTesting();
 
   const autofill::CreditCard card = autofill::test::GetCreditCard2();  // Amex.
   AddCreditCard(card);
 
   CallCanMakePayment();
 
   // Returns true because the user is in incognito mode, even though it should
   // return false in a normal profile.
   ExpectBodyContains(std::vector<base::string16>{base::ASCIIToUTF16("true")});
 }
 
 }  // namespace payments