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

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

Index: chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc
diff --git a/chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc b/chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc
index 707ddf804bb19cb9313bc5498f29f9ca4500c095..8752435eaaedb27fd60ef42c2747ecb291b2f733 100644
--- a/chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc
+++ b/chrome/browser/ui/views/payments/payment_request_can_make_payment_browsertest.cc
@@ -21,7 +21,9 @@ class PaymentRequestCanMakePaymentQueryTest
             "/payment_request_can_make_payment_query_test.html") {}
 
   void CallCanMakePayment() {
+    ResetEventObserver(DialogEvent::CAN_MAKE_PAYMENT_CALLED);
     ASSERT_TRUE(content::ExecuteScript(GetActiveWebContents(), "buy();"));
+    WaitForObservedEvent();
   }
 
  private:
@@ -29,9 +31,8 @@ class 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);
 
@@ -67,9 +68,8 @@ IN_PROC_BROWSER_TEST_F(PaymentRequestCanMakePaymentQueryTest,
 
 // 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.