Upstream Chrome on iOS source code [5/11].

ios/chrome/browser/ui/fancy_ui/tinted_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.
+
+#include "ios/chrome/browser/ui/fancy_ui/tinted_button.h"
+
+#import "base/mac/scoped_nsobject.h"
+
+@interface TintedButton () {
+  base::scoped_nsobject<UIColor> normalStateTint_;
+  base::scoped_nsobject<UIColor> highlightedTint_;
+}
+
+// Makes the button's tint color reflect its current state.
+- (void)updateTint;
+
+@end
+
+@implementation TintedButton
+
+- (void)setTintColor:(UIColor*)color forState:(UIControlState)state {
+  switch (state) {
+    case UIControlStateNormal:
+      normalStateTint_.reset([color copy]);
+      break;
+    case UIControlStateHighlighted:
+      highlightedTint_.reset([color copy]);
+      break;
+    default:
+      return;
+  }
+
+  if (normalStateTint_ || highlightedTint_)
+    self.adjustsImageWhenHighlighted = NO;
+  else
+    self.adjustsImageWhenHighlighted = YES;
+  [self updateTint];
+}
+
+#pragma mark - UIControl
+
+- (void)setHighlighted:(BOOL)highlighted {
+  [super setHighlighted:highlighted];
+  [self updateTint];
+}
+
+#pragma mark - Private
+
+- (void)updateTint {
+  UIColor* newTint = nil;
+  switch (self.state) {
+    case UIControlStateNormal:
+      newTint = normalStateTint_.get();
+      break;
+    case UIControlStateHighlighted:
+      newTint = highlightedTint_.get();
+      break;
+    default:
+      newTint = normalStateTint_.get();
+      break;
+  }
+  self.tintColor = newTint;
+}
+
+@end