[Payment Request] Moves PaymentRequest into the payments namespace

ios/chrome/browser/ui/payments/payment_items_display_mediator.mm

Index: ios/chrome/browser/ui/payments/payment_items_display_mediator.mm
diff --git a/ios/chrome/browser/ui/payments/payment_items_display_mediator.mm b/ios/chrome/browser/ui/payments/payment_items_display_mediator.mm
index 2ba9d9bd75ddb97d732a239d07a5e6d74de12997..8c7e081e169a7bffff66bf123545e78a3b6d7cab 100644
--- a/ios/chrome/browser/ui/payments/payment_items_display_mediator.mm
+++ b/ios/chrome/browser/ui/payments/payment_items_display_mediator.mm
@@ -24,7 +24,7 @@
 // The PaymentRequest object owning an instance of web::PaymentRequest as
 // provided by the page invoking the Payment Request API. This is a weak
 // pointer and should outlive this class.
-@property(nonatomic, assign) PaymentRequest* paymentRequest;
+@property(nonatomic, assign) payments::PaymentRequest* paymentRequest;
 
 @end
 
@@ -32,7 +32,8 @@
 
 @synthesize paymentRequest = _paymentRequest;
 
-- (instancetype)initWithPaymentRequest:(PaymentRequest*)paymentRequest {
+- (instancetype)initWithPaymentRequest:
+    (payments::PaymentRequest*)paymentRequest {
   self = [super init];
   if (self) {
     _paymentRequest = paymentRequest;