[Mac] Implement an active state for the avatar button

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

Index: chrome/browser/ui/cocoa/profiles/avatar_button.mm
diff --git a/chrome/browser/ui/cocoa/profiles/avatar_button.mm b/chrome/browser/ui/cocoa/profiles/avatar_button.mm
index a1d5c12c1c0122bfd5661dfa6b51480b16aa304c..616d7ac13ca267faf3c752ad322d7d526259d0a9 100644
--- a/chrome/browser/ui/cocoa/profiles/avatar_button.mm
+++ b/chrome/browser/ui/cocoa/profiles/avatar_button.mm
@@ -13,6 +13,8 @@
 
 @implementation AvatarButton
 
+@synthesize isActive = isActive_;
+
 // Overrides -rightMouseDown and implements a custom mouse tracking loop.
 - (void)rightMouseDown:(NSEvent*)event {
   NSEvent* nextEvent = event;
@@ -45,4 +47,10 @@
   rightAction_ = selector;
 }
 
+- (void)setIsActive:(BOOL)isActive {
+  BOOL activeChanged = isActive_ != isActive;
+  isActive_ = isActive;
+  [self setNeedsDisplay:activeChanged];
+}
+
 @end