Remove SigninDelegateObserver.

chrome/browser/ui/app_list/chrome_signin_delegate.cc

Index: chrome/browser/ui/app_list/chrome_signin_delegate.cc
diff --git a/chrome/browser/ui/app_list/chrome_signin_delegate.cc b/chrome/browser/ui/app_list/chrome_signin_delegate.cc
index e74ca6f454a200a1a7c6438f7e25431b68b7fe7b..e7d0aa4228316f8fb225b152f41c6c7d1d61aaa0 100644
--- a/chrome/browser/ui/app_list/chrome_signin_delegate.cc
+++ b/chrome/browser/ui/app_list/chrome_signin_delegate.cc
@@ -18,7 +18,6 @@
 #include "content/public/common/page_transition_types.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
-#include "ui/app_list/signin_delegate_observer.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace {
@@ -49,8 +48,6 @@ bool ChromeSigninDelegate::NeedSignin()  {
 void ChromeSigninDelegate::ShowSignin() {
   DCHECK(profile_);
 
-  signin_tracker_.reset(new SigninTracker(profile_, this));
-
   Browser* browser = FindOrCreateTabbedBrowser(profile_,
                                                chrome::GetActiveDesktop());
   chrome::ShowBrowserSignin(browser, signin::SOURCE_APP_LAUNCHER);
@@ -101,9 +98,3 @@ string16 ChromeSigninDelegate::GetSettingsLinkText() {
 }
 
 ChromeSigninDelegate::~ChromeSigninDelegate() {}
-
-void ChromeSigninDelegate::SigninFailed(const GoogleServiceAuthError& error) {}
-
-void ChromeSigninDelegate::SigninSuccess() {
-  NotifySigninSuccess();
-}