cocoa: darken toolbar buttons in Increase Contrast mode

chrome/browser/ui/cocoa/toolbar/app_toolbar_button.mm

 // Copyright 2016 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.
 
 #import "chrome/browser/ui/cocoa/toolbar/app_toolbar_button.h"
 
 #include "base/macros.h"
 #include "chrome/app/vector_icons/vector_icons.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #import "chrome/browser/ui/cocoa/view_id_util.h"
 #include "ui/base/material_design/material_design_controller.h"
+#include "ui/base/theme_provider.h"
 #include "ui/gfx/color_palette.h"
 
 @interface AppToolbarButton ()
 - (void)commonInit;
 @end
 
 @implementation AppToolbarButton
 
 - (instancetype)initWithFrame:(NSRect)frame {
   if ((self = [super initWithFrame:frame])) {
@@ skipping 21 matching lines @@
       return &kBrowserToolsUpdateIcon;
     case AppMenuIconController::IconType::GLOBAL_ERROR:
     case AppMenuIconController::IconType::INCOMPATIBILITY_WARNING:
       return &kBrowserToolsErrorIcon;
   }
 
   return nullptr;
 }
 
 - (SkColor)vectorIconColor:(BOOL)themeIsDark {
+  const ui::ThemeProvider* provider = [[self window] themeProvider];
   switch (severity_) {
     case AppMenuIconController::Severity::NONE:
-      return themeIsDark ? SK_ColorWHITE : gfx::kChromeIconGrey;
+      return themeIsDark ? SK_ColorWHITE
+                         : provider && provider->ShouldIncreaseContrast()

[Mark Mentovai, 2017/02/23 01:54:16]

I suggest but don’t require (parentheses) around everything after the first
colon to answer the question “does this do what it means?” without having to
refer to a precedence table. (Yeah, it does do what it means here…)

+                               ? SK_ColorBLACK
+                               : gfx::kChromeIconGrey;
       break;
 
     case AppMenuIconController::Severity::LOW:
       return themeIsDark ? gfx::kGoogleGreen300 : gfx::kGoogleGreen700;
       break;
 
     case AppMenuIconController::Severity::MEDIUM:
       return themeIsDark ? gfx::kGoogleYellow300 : gfx::kGoogleYellow700;
       break;
 
@@ skipping 11 matching lines @@
       shouldAnimate:(BOOL)shouldAnimate {
   if (severity != severity_ || type != type_) {
     severity_ = severity;
     type_ = type;
     // Update the button state images with the new severity color or icon type.
     [self resetButtonStateImages];
   }
 }
 
 @end