Implement the new Sync Confirmation dialog on Linux and Windows.

chrome/browser/ui/views/profiles/signin_view_controller.h

Index: chrome/browser/ui/views/profiles/signin_view_controller.h
diff --git a/chrome/browser/ui/views/profiles/signin_view_controller.h b/chrome/browser/ui/views/profiles/signin_view_controller.h
index fdc3b923c0593c36e0a0627b59750095ca234c49..0372accb5d9a7db984d36d21bf6ad53da3d77287 100644
--- a/chrome/browser/ui/views/profiles/signin_view_controller.h
+++ b/chrome/browser/ui/views/profiles/signin_view_controller.h
@@ -42,6 +42,8 @@ class SigninViewController {
       Profile* profile,
       signin_metrics::AccessPoint access_point);
 
+  static views::WebView* CreateSyncConfirmationWebView(Profile* profile);
+
   // Shows the signin flow as a tab modal dialog attached to |browser|'s active
   // web contents.
   // |access_point| indicates the access point used to open the Gaia sign in
@@ -50,6 +52,8 @@ class SigninViewController {
                        Browser* browser,
                        signin_metrics::AccessPoint access_point);
 
+  void ShowModalSyncConfirmationDialog(Browser* browser);
+
   // Closes the tab-modal signin flow previously shown using this
   // SigninViewController, if one exists. Does nothing otherwise.
   void CloseModalSignin();