[CRD iOS] Implementing save to keychain and user defaults for login info. Refactor remoting service.

remoting/client/ios/app/remoting_settings_view_controller.mm

Index: remoting/client/ios/app/remoting_settings_view_controller.mm
diff --git a/remoting/client/ios/app/remoting_settings_view_controller.mm b/remoting/client/ios/app/remoting_settings_view_controller.mm
index da3c0cd8bd4795abdeafc087cb5a8b5af0f71213..1db1db01c8c9dd0b913326d761e7b9d438107c1c 100644
--- a/remoting/client/ios/app/remoting_settings_view_controller.mm
+++ b/remoting/client/ios/app/remoting_settings_view_controller.mm
@@ -10,6 +10,8 @@
 
 #import "ios/third_party/material_components_ios/src/components/AppBar/src/MaterialAppBar.h"
 #import "ios/third_party/material_components_ios/src/components/Buttons/src/MaterialButtons.h"
+#import "remoting/client/ios/facade/remoting_authentication.h"
+#import "remoting/client/ios/facade/remoting_service.h"
 
 #include "base/strings/stringprintf.h"
 #include "google_apis/google_api_keys.h"
@@ -113,7 +115,7 @@ std::string GetAuthorizationCodeUri() {
   self.styler.cellStyle = MDCCollectionViewCellStyleCard;
 
   _content = [NSMutableArray array];
-  [_content addObject:@[ @"Login" ]];
+  [_content addObject:@[ @"Login", @"Logout" ]];
 }
 
 #pragma mark - UICollectionViewDataSource
@@ -146,10 +148,17 @@ std::string GetAuthorizationCodeUri() {
                forControlEvents:UIControlEventTouchUpInside];
     accessCodeButton.translatesAutoresizingMaskIntoConstraints = NO;
     cell.accessoryView = accessCodeButton;
-  } else {
-    UISwitch* editingSwitch = [[UISwitch alloc] initWithFrame:CGRectZero];
-    cell.accessoryView = editingSwitch;
+  } else if (indexPath.section == 0 && indexPath.item == 1) {
+    MDCRaisedButton* logoutButton = [[MDCRaisedButton alloc] init];
+    [logoutButton setTitle:@"Logout" forState:UIControlStateNormal];
+    [logoutButton sizeToFit];
+    [logoutButton addTarget:self
+                     action:@selector(didTapLogout:)
+           forControlEvents:UIControlEventTouchUpInside];
+    logoutButton.translatesAutoresizingMaskIntoConstraints = NO;
+    cell.accessoryView = logoutButton;
   }
+
   return cell;
 }
 
@@ -192,4 +201,8 @@ std::string GetAuthorizationCodeUri() {
   [[UIApplication sharedApplication] openURL:[NSURL URLWithString:authUri]];
 }
 
+- (void)didTapLogout:(id)sender {
+  [[RemotingService SharedInstance].authentication logout];
+}
+
 @end