EarlGrey tests for Payment Request (base CL)

ios/chrome/browser/payments/payment_request_manager.mm

Index: ios/chrome/browser/payments/payment_request_manager.mm
diff --git a/ios/chrome/browser/payments/payment_request_manager.mm b/ios/chrome/browser/payments/payment_request_manager.mm
index 657183145f2098c5333df7c8a8daa4518e4d0ad9..5cec27fa7e84b558a408cacdc86dff00d22d7992 100644
--- a/ios/chrome/browser/payments/payment_request_manager.mm
+++ b/ios/chrome/browser/payments/payment_request_manager.mm
@@ -15,6 +15,7 @@
 #include "components/autofill/core/browser/personal_data_manager.h"
 #include "ios/chrome/browser/autofill/personal_data_manager_factory.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/experimental_flags.h"
 #import "ios/chrome/browser/payments/js_payment_request_manager.h"
 #import "ios/chrome/browser/payments/payment_request_coordinator.h"
 #import "ios/chrome/browser/payments/payment_request_web_state_observer.h"
@@ -123,7 +124,6 @@ const std::string kCommandPrefix = "paymentRequest";
                 instanceOfClass:[JSPaymentRequestManager class]]));
     _webState = webState;
     _webStateObserver->ObserveWebState(webState);
-    [self enableCurrentWebState];

[Justin Donnelly, 2016/12/29 18:36:57]

I'm skeptical that this is ok. The web state has a rather complex life cycle I
believe based on navigations, redirects, going back, reloads, etc. I copied this
particular setup from another JS injected feature and I assume it was designed
carefully to work in all circumstances. Maybe lpromero knows or else we can
track down someone who can better answer than I can if this will work in all
cases.

[Moe, 2017/01/06 16:16:27]

lpromero@ I was wondering if you had any feedback on the point justin made.

[lpromero, 2017/01/06 16:20:01]

eugenebut@ would probably be the right person to ask.

[Moe, 2017/01/06 16:25:21]

eugenebut@ could please chime in?

[Eugene But (OOO till 7-30), 2017/01/06 17:36:22]

I don't know what |enableCurrentWebState| does. This method has no comment. 

[Justin Donnelly, 2017/01/06 18:21:07]

I copied the existing pattern of calls and state transitions from
contextual_search_controller.mm. marq@, did you make that? Can you comment on
whether the new setup mahmadi@ is making here will work in all circumstances?

[marq (ping after 24h), 2017/01/09 17:55:38]

I'll have to look over it carefully; the use cases for
ContextualSearchController are fairly specific.

   } else {
     _webState = nullptr;
   }
@@ -146,7 +146,6 @@ const std::string kCommandPrefix = "paymentRequest";
       [self dismissUI];
     }
     _enabled = enabled;
-    [self enableCurrentWebState];
   }
 }
 
@@ -167,7 +166,7 @@ const std::string kCommandPrefix = "paymentRequest";
 }
 
 - (void)enableCurrentWebState {
-  if (![self webState]) {
+  if (![self webState] || !experimental_flags::IsPaymentRequestEnabled()) {
     return;
   }