Add generic PaletteDelegate code.

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index 1ec0dbe30a073898f784f0d187a943b9f8c3d465..70753a08b81e99222369a1147d3a1decfcd10cb8 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -50,6 +50,7 @@
 #include "chrome/browser/ui/ash/launcher/launcher_context_menu.h"
 #include "chrome/browser/ui/ash/media_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_util.h"
+#include "chrome/browser/ui/ash/palette_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/session_state_delegate_chromeos.h"
 #include "chrome/browser/ui/ash/session_util.h"
 #include "chrome/browser/ui/ash/system_tray_delegate_chromeos.h"
@@ -507,6 +508,11 @@ ash::MediaDelegate* ChromeShellDelegate::CreateMediaDelegate() {
   return new MediaDelegateChromeOS;
 }
 
+std::unique_ptr<ash::PaletteDelegate>
+ChromeShellDelegate::CreatePaletteDelegate() {
+  return base::WrapUnique(new chromeos::PaletteDelegateChromeOS());
+}
+
 ash::SystemTrayDelegate* ChromeShellDelegate::CreateSystemTrayDelegate() {
   return chromeos::CreateSystemTrayDelegate();
 }