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

components/payments/content/payment_request_web_contents_manager.h

 // 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.
 
 #ifndef COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_
 #define COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_
 
 #include <memory>
 #include <unordered_map>
 
 #include "base/macros.h"
+#include "components/payments/content/payment_request.h"
 #include "components/payments/content/payment_request.mojom.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace content {
 class WebContents;
 }
 
 namespace payments {
 
-class PaymentRequest;
 class PaymentRequestDelegate;
 
 // This class owns the PaymentRequest associated with a given WebContents.
 //
 // Responsible for creating PaymentRequest's and retaining ownership. No request
 // pointers are currently available because the request manages its interactions
 // with UI and renderer. The PaymentRequest may call DestroyRequest() to signal
 // it is ready to die. Otherwise it gets destroyed when the WebContents (thus
 // this class) goes away.
 class PaymentRequestWebContentsManager
     : public content::WebContentsUserData<PaymentRequestWebContentsManager> {
  public:
   ~PaymentRequestWebContentsManager() override;
 
   // Retrieves the instance of PaymentRequestWebContentsManager that was
   // attached to the specified WebContents.  If no instance was attached,
   // creates one, and attaches it to the specified WebContents.
   static PaymentRequestWebContentsManager* GetOrCreateForWebContents(
       content::WebContents* web_contents);
 
   // Creates the PaymentRequest that will interact with this |web_contents|.
   void CreatePaymentRequest(
       content::WebContents* web_contents,
       std::unique_ptr<PaymentRequestDelegate> delegate,
-      mojo::InterfaceRequest<payments::mojom::PaymentRequest> request);
+      mojo::InterfaceRequest<payments::mojom::PaymentRequest> request,
+      PaymentRequest::ObserverForTest* observer_for_testing);
 
   // Destroys the given |request|.
   void DestroyRequest(PaymentRequest* request);
 
  private:
   explicit PaymentRequestWebContentsManager(content::WebContents* web_contents);
   friend class content::WebContentsUserData<PaymentRequestWebContentsManager>;
   friend class PaymentRequestBrowserTestBase;
 
   // Owns all the PaymentRequest for this WebContents. Since the
   // PaymentRequestWebContentsManager's lifetime is tied to the WebContents,
   // these requests only get destroyed when the WebContents goes away, or when
   // the requests themselves call DestroyRequest().
   std::unordered_map<PaymentRequest*, std::unique_ptr<PaymentRequest>>
       payment_requests_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestWebContentsManager);
 };
 
 }  // namespace payments
 
 #endif  // COMPONENTS_PAYMENTS_PAYMENT_REQUEST_WEB_CONTENTS_MANAGER_H_