Add SetProminent() to MdTextButton to create blue buttons.

ui/native_theme/native_theme_mac.mm

 // Copyright (c) 2013 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.
 
 #include "ui/native_theme/native_theme_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/mac/mac_util.h"
@@ skipping 173 matching lines @@
 
     // Buttons and labels.
     case kColorId_ButtonBackgroundColor:
     case kColorId_ButtonHoverBackgroundColor:
     case kColorId_HoverMenuButtonBorderColor:
     case kColorId_LabelBackgroundColor:
       return NSSystemColorToSkColor([NSColor controlBackgroundColor]);
     case kColorId_ButtonEnabledColor:
     case kColorId_EnabledMenuButtonBorderColor:
     case kColorId_LabelEnabledColor:
-    case kColorId_CallToActionColor:
+    case kColorId_ProminentButtonColor:
       return NSSystemColorToSkColor([NSColor controlTextColor]);
     case kColorId_ButtonDisabledColor:
     case kColorId_LabelDisabledColor:
       return NSSystemColorToSkColor([NSColor disabledControlTextColor]);
     case kColorId_ButtonHighlightColor:
       // Although the NSColor documentation names "selectedControlTextColor" as
       // the color for a "text in a .. control being clicked or dragged", it
       // remains black, and text on Yosemite-style pressed buttons is white.
       return SK_ColorWHITE;
     case kColorId_ButtonHoverColor:
@@ skipping 231 matching lines @@
   canvas->drawDRRect(outer_shape, shape, paint);
 }
 
 NativeThemeMac::NativeThemeMac() {
 }
 
 NativeThemeMac::~NativeThemeMac() {
 }
 
 }  // namespace ui