Add SetProminent() to MdTextButton to create blue buttons.

ui/views/controls/button/md_text_button.h

 // Copyright 2015 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 UI_VIEWS_CONTROLS_BUTTON_MD_TEXT_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_MD_TEXT_BUTTON_H_
 
 #include <memory>
 
 #include "base/optional.h"
@@ skipping 14 matching lines @@
                                            const base::string16& text);
   // As above, but only creates an MdTextButton if MD is enabled in the
   // secondary UI (as opposed to just "top chrome"/"primary" UI).
   static LabelButton* CreateSecondaryUiButton(ButtonListener* listener,
                                               const base::string16& text);
   static LabelButton* CreateSecondaryUiBlueButton(ButtonListener* listener,
                                                   const base::string16& text);
   static MdTextButton* Create(ButtonListener* listener,
                               const base::string16& text);
 
-  // See |is_cta_|.
-  void SetCallToAction(bool cta);
+  // See |is_prominent_|.
+  void SetProminent(bool is_prominent);
   void set_bg_color_override(SkColor color) { bg_color_override_ = color; }
 
   // LabelButton:
   void Layout() override;
   void OnFocus() override;
   void OnBlur() override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
   std::unique_ptr<views::InkDropRipple> CreateInkDropRipple() const override;
   std::unique_ptr<views::InkDropHighlight> CreateInkDropHighlight()
       const override;
@@ skipping 14 matching lines @@
   ~MdTextButton() override;
 
   void UpdatePadding();
   void UpdateColors();
 
   // The MD-style focus ring. This is not done via a FocusPainter
   // because it needs to paint to a layer so it can extend beyond the bounds of
   // |this|.
   internal::MdFocusRing* focus_ring_;
 
-  // True if this button uses call-to-action styling.
-  bool is_cta_;
+  // True if this button uses prominent styling (blue fill, etc.).
+  bool is_prominent_;
 
   // When set, this provides the background color.
   base::Optional<SkColor> bg_color_override_;
 
   DISALLOW_COPY_AND_ASSIGN(MdTextButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_MD_TEXT_BUTTON_H_