[Autofill] Tweak credit card signin promo visually.

chrome/browser/ui/autofill/autofill_popup_controller.h

 // Copyright (c) 2012 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_AUTOFILL_AUTOFILL_POPUP_CONTROLLER_H_
 #define CHROME_BROWSER_UI_AUTOFILL_AUTOFILL_POPUP_CONTROLLER_H_
 
 #include <stddef.h>
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/autofill/autofill_popup_view_delegate.h"
+#include "third_party/skia/include/core/SkColor.h"
 
 namespace gfx {
 class FontList;
 class Point;
 class Rect;
 }
 
 namespace autofill {
 
 class AutofillPopupLayoutModel;
@@ skipping 29 matching lines @@
   // Removes the suggestion at the given index.
   virtual bool RemoveSuggestion(int index) = 0;
 
 #if !defined(OS_ANDROID)
   // The same font can vary based on the type of data it is showing,
   // so we need to know the row.
   virtual const gfx::FontList& GetValueFontListForRow(size_t index) const = 0;
   virtual const gfx::FontList& GetLabelFontList() const = 0;
 #endif
 
+  // Returns the background color of the row item according to its |index|, or
+  // transparent if the default popup background should be used.
+  virtual SkColor GetBackgroundColorForRow(int index) const = 0;
+
   // Returns the index of the selected line. A line is "selected" when it is
   // hovered or has keyboard focus.
   virtual int selected_line() const = 0;
 
   virtual const AutofillPopupLayoutModel& layout_model() const = 0;
 
  protected:
   ~AutofillPopupController() override {}
 };
 
 }  // namespace autofill
 
 #endif  // CHROME_BROWSER_UI_AUTOFILL_AUTOFILL_POPUP_CONTROLLER_H_