[iOS] Add experimental new keyboard accessory view.

ios/chrome/browser/ui/fancy_ui/colored_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"
+#include "ios/chrome/browser/ui/fancy_ui/colored_button.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-@interface TintedButton () {
+@interface ColoredButton () {
   UIColor* normalStateTint_;
   UIColor* highlightedTint_;
+  UIColor* normalStateBackgroundColor_;
+  UIColor* highlightedBackgroundColor_;
 }
 
 // Makes the button's tint color reflect its current state.
 - (void)updateTint;
 
+// Makes the button's background color reflect its current state.
+- (void)updateBackgroundColor;
+
 @end
 
-@implementation TintedButton
+@implementation ColoredButton
 
 - (void)setTintColor:(UIColor*)color forState:(UIControlState)state {
   switch (state) {
     case UIControlStateNormal:
       normalStateTint_ = [color copy];
       break;
     case UIControlStateHighlighted:
       highlightedTint_ = [color copy];
       break;
     default:
       return;
   }
 
   if (normalStateTint_ || highlightedTint_)
     self.adjustsImageWhenHighlighted = NO;
   else
     self.adjustsImageWhenHighlighted = YES;
   [self updateTint];
 }
 
+- (void)setBackgroundColor:(UIColor*)color forState:(UIControlState)state {
+  switch (state) {
+    case UIControlStateNormal:
+      normalStateBackgroundColor_ = [color copy];
+      break;
+    case UIControlStateHighlighted:
+      highlightedBackgroundColor_ = [color copy];
+      break;
+    default:
+      return;
+  }
+
+  [self updateBackgroundColor];
+}
+
 #pragma mark - UIControl
 
 - (void)setHighlighted:(BOOL)highlighted {
   [super setHighlighted:highlighted];
   [self updateTint];
+  [self updateBackgroundColor];
 }
 
 #pragma mark - Private
 
 - (void)updateTint {
   UIColor* newTint = nil;
   switch (self.state) {
     case UIControlStateNormal:
       newTint = normalStateTint_;
       break;
     case UIControlStateHighlighted:
       newTint = highlightedTint_;
       break;
     default:
       newTint = normalStateTint_;
       break;
   }
   self.tintColor = newTint;
 }
 
+- (void)updateBackgroundColor {
+  UIColor* newBackgroundColor = nil;
+  switch (self.state) {
+    case UIControlStateNormal:
+      newBackgroundColor = normalStateBackgroundColor_;
+      break;
+    case UIControlStateHighlighted:
+      newBackgroundColor = highlightedBackgroundColor_;
+      break;
+    default:
+      newBackgroundColor = normalStateBackgroundColor_;
+      break;
+  }
+  self.backgroundColor = newBackgroundColor;
+}
+
 @end