Revert of Aura Android: ShowBrowserSignin is not defined for Android, use NOTIMPLEMENTED for now

chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc

Index: chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
diff --git a/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc b/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
index cdc3df7112b61c0bbc09fdbaa340ea9714077258..e06a3567edc3df866d5e7fdddd6cf903e5d53f7f 100644
--- a/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
+++ b/chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc
@@ -286,14 +286,8 @@
   GetWidget()->Close();
 
   if (source == sign_in_link_) {
-#if defined(OS_ANDROID)
-    // TODO(bshe): Figure out what to do on Android platform. See
-    // crbug.com/559340.
-    NOTIMPLEMENTED();
-#else
     chrome::ShowBrowserSignin(
         browser_, signin_metrics::SOURCE_EXTENSION_INSTALL_BUBBLE);
-#endif
     return;
   }