[Payments] Add combobox support to editors.

chrome/browser/ui/views/payments/validating_textfield.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 CHROME_BROWSER_UI_VIEWS_PAYMENTS_VALIDATING_TEXTFIELD_H_
 #define CHROME_BROWSER_UI_VIEWS_PAYMENTS_VALIDATING_TEXTFIELD_H_
 
 #include "base/macros.h"
+#include "chrome/browser/ui/views/payments/validation_delegate.h"
 #include "ui/views/controls/textfield/textfield.h"
 
 namespace payments {
 
 class ValidatingTextfield : public views::Textfield {
  public:
-  class Delegate {
-   public:
-    Delegate() {}
-    virtual ~Delegate() {}
-
-    // Only the delegate knows how to validate the textfield.
-    virtual bool ValidateTextfield(views::Textfield* textfield) = 0;
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(Delegate);
-  };
-
-  explicit ValidatingTextfield(
-      std::unique_ptr<ValidatingTextfield::Delegate> delegate);
+  explicit ValidatingTextfield(std::unique_ptr<ValidationDelegate> delegate);
   ~ValidatingTextfield() override;
 
   // Textfield:
   // The first validation will happen on blur.
   void OnBlur() override;
 
   // Called when the textfield contents is changed. May do validation.
   void OnContentsChanged();
 
  private:
-  // Will call to the Delegate to validate the contents of the textfield.
+  // Will call to the ValidationDelegate to validate the contents of the
+  // textfield.
   void Validate();
 
-  std::unique_ptr<ValidatingTextfield::Delegate> delegate_;
-  bool was_validated_ = false;
+  std::unique_ptr<ValidationDelegate> delegate_;
+  bool was_blurred_;
 
   DISALLOW_COPY_AND_ASSIGN(ValidatingTextfield);
 };
 
 }  // namespace payments
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PAYMENTS_VALIDATING_TEXTFIELD_H_