[Mac] Implement an active state for the avatar button

chrome/browser/ui/cocoa/profiles/avatar_button.mm

 // Copyright 2015 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/profiles/avatar_button.h"
 
 @interface AvatarButton (Private)
 
 - (void)rightMouseDown:(NSEvent*)event;
 - (void)performRightClick;
 
 @end
 
 @implementation AvatarButton
 
+@synthesize isActive = isActive_;
+
 // Overrides -rightMouseDown and implements a custom mouse tracking loop.
 - (void)rightMouseDown:(NSEvent*)event {
   NSEvent* nextEvent = event;
   BOOL mouseInBounds = NO;
   hoverState_ = kHoverStateMouseDown;
 
   do {
     nextEvent = [[self window]
         nextEventMatchingMask:NSRightMouseDraggedMask |
                               NSRightMouseUpMask];
@@ skipping 12 matching lines @@
 }
 
 - (void)performRightClick {
   [[super target] performSelector:rightAction_ withObject:self];
 }
 
 - (void)setRightAction:(SEL)selector {
   rightAction_ = selector;
 }
 
+- (void)setIsActive:(BOOL)isActive {
+  BOOL activeChanged = isActive_ != isActive;
+  isActive_ = isActive;
+  [self setNeedsDisplay:activeChanged];
+}
+
 @end