cocoa: draw tabstrip stroke in white in increase-contrast incognito

chrome/browser/ui/cocoa/tabs/tab_strip_view.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_view.h"
 
 #include <cmath>  // floor
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
@@ skipping 67 matching lines @@
     if ([window isMainWindow]) {
       strokeColor = themeProvider->GetNSColor(
           ThemeProperties::COLOR_TOOLBAR_STROKE_THEME);
     } else {
       strokeColor = themeProvider->GetNSColor(
           ThemeProperties::COLOR_TOOLBAR_STROKE_THEME_INACTIVE);
     }
   } else {
     strokeColor =
         themeProvider->GetNSColor(ThemeProperties::COLOR_TOOLBAR_STROKE);
+
+    // If the current theme is the system theme, and the system is in "increase
+    // contrast" mode, and this is an incognito window, force the toolbar stroke
+    // to be drawn in white instead of black, to make it show up better.
+    if ([[self window] hasDarkTheme] && themeProvider->ShouldIncreaseContrast())
+      strokeColor = [NSColor whiteColor];
   }
 
   if (themeProvider->ShouldIncreaseContrast())
     strokeColor = [strokeColor colorWithAlphaComponent:100];
   [strokeColor set];
 
   NSRect borderRect = NSMakeRect(0.0, 0.0, self.bounds.size.width,
       [self cr_lineWidth]);
   NSRectFillUsingOperation(NSIntersectionRect(dirtyRect, borderRect),
                            NSCompositeSourceOver);
@@ skipping 324 matching lines @@
   if (visualEffectsDisabledForFullscreen_ ||
       themeProvider->HasCustomImage(IDR_THEME_FRAME) ||
       themeProvider->HasCustomColor(ThemeProperties::COLOR_FRAME)) {
     [visualEffectView setState:NSVisualEffectStateInactive];
   } else {
     [visualEffectView setState:NSVisualEffectStateFollowsWindowActiveState];
   }
 }
 
 @end