[Payment Request] Populates country field if country code/name is valid.

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

 // 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.
 
 #import "ios/chrome/browser/ui/payments/address_edit_mediator.h"
 
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
@@ skipping 135 matching lines @@
   // field value is set to the respective region code. Otherwise, it is set to
   // nil.
   self.regionField.value = nil;
   if (self.address) {
     NSString* region =
         [self fieldValueFromProfile:self.address
                           fieldType:autofill::ADDRESS_HOME_STATE];
     if ([regions objectForKey:region]) {
       self.regionField.value = region;
     } else if ([[regions allKeysForObject:region] count]) {
-      DCHECK(1 == [[regions allKeysForObject:region] count]);
+      DCHECK_EQ(1U, [[regions allKeysForObject:region] count]);
       self.regionField.value = [regions allKeysForObject:region][0];
     }
   }
 
   // Notify the view controller asynchronously to allow for the view to update.
   __weak AddressEditMediator* weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
     [weakSelf.consumer setOptions:@[ [regions allKeys] ]
                    forEditorField:weakSelf.regionField];
   });
@@ skipping 15 matching lines @@
           initWithCapacity:static_cast<NSUInteger>(countriesVector.size())];
   for (size_t i = 0; i < countriesVector.size(); ++i) {
     if (countriesVector[i].get()) {
       [countries setObject:base::SysUTF16ToNSString(countriesVector[i]->name())
                     forKey:base::SysUTF8ToNSString(
                                countriesVector[i]->country_code())];
     }
   }
   _countries = countries;
 
-  // If an address is being edited and it has a valid country code, the selected
-  // country code is set to that value. Otherwise, it is set to the default
-  // country code.
-  NSString* countryCode =
+  // If an address is being edited and it has a valid country code or a valid
+  // country name for the autofill::ADDRESS_HOME_COUNTRY field, the selected
+  // country code is set to the respective country code. Otherwise, the selected
+  // country code is set to the default country code.
+  NSString* country =
       [self fieldValueFromProfile:_address
                         fieldType:autofill::ADDRESS_HOME_COUNTRY];
-  _selectedCountryCode =
-      countryCode && [_countries objectForKey:countryCode]
-          ? countryCode
-          : base::SysUTF8ToNSString(countryModel.GetDefaultCountryCode());
+
+  if ([countries objectForKey:country]) {
+    _selectedCountryCode = country;
+  } else if ([[countries allKeysForObject:country] count]) {
+    DCHECK_EQ(1U, [[countries allKeysForObject:country] count]);
+    _selectedCountryCode = [countries allKeysForObject:country][0];
+  } else {
+    _selectedCountryCode =
+        base::SysUTF8ToNSString(countryModel.GetDefaultCountryCode());
+  }
 }
 
 // Queries the region names based on the selected country code.
 - (void)loadRegions {
   _regionDataLoader = base::MakeUnique<RegionDataLoader>(self);
   _regionDataLoader->LoadRegionData(
       base::SysNSStringToUTF8(self.selectedCountryCode),
       _paymentRequest->GetRegionDataLoader());
 }
 
@@ skipping 131 matching lines @@
 // corresponding field value. Returns nil if |profile| is nullptr.
 - (NSString*)fieldValueFromProfile:(autofill::AutofillProfile*)profile
                          fieldType:(autofill::ServerFieldType)fieldType {
   return profile ? base::SysUTF16ToNSString(profile->GetInfo(
                        autofill::AutofillType(fieldType),
                        GetApplicationContext()->GetApplicationLocale()))
                  : nil;
 }
 
 @end