Update code so 1:1 relation between delegate and router is more clear.

chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc

Index: chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc
diff --git a/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc b/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc
index a8c0952668a84a306d01de00cc1202f1fbd2c68c..6c01b2f3211ab5ed100ed587b0d8fc431a8f4321 100644
--- a/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc
+++ b/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.cc
@@ -12,6 +12,7 @@
 #include "base/bind_helpers.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/api/passwords_private/passwords_private_delegate.h"
 #include "chrome/browser/extensions/api/passwords_private/passwords_private_delegate_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/passwords_private.h"
@@ -22,9 +23,7 @@ namespace extensions {
 PasswordsPrivateEventRouter::PasswordsPrivateEventRouter(
     content::BrowserContext* context)
     : context_(context),
-      event_router_(nullptr),
-      listening_(false),
-      ignore_updates_(false) {
+      event_router_(nullptr) {
   // Register with the event router so we know when renderers are listening to
   // our events. We first check and see if there *is* an event router, because
   // some unit tests try to create all context services, but don't initialize
@@ -49,33 +48,16 @@ PasswordsPrivateEventRouter::~PasswordsPrivateEventRouter() {}
 void PasswordsPrivateEventRouter::Shutdown() {
   if (event_router_)
     event_router_->UnregisterObserver(this);
-
-  PasswordsPrivateDelegate* delegate =
-      PasswordsPrivateDelegateFactory::GetForBrowserContext(context_,
-                                                            false /* create */);
-  if (delegate)
-    delegate->RemoveObserver(this);
 }
 
 void PasswordsPrivateEventRouter::OnListenerAdded(
     const EventListenerInfo& details) {
-  // Start listening to change events and propagate the original lists to
-  // listeners.
-  {
-    // Some delegates will immediately update observers. Since we dispatch the
-    // events again below, we want to ignore this here.
-    // TODO(stevenjb): Fix this. crbug.com/598826.
-    base::AutoReset<bool> ignore_updates(&ignore_updates_, true);
-    StartOrStopListeningForChanges();
+  PasswordsPrivateDelegate* delegate =
+      PasswordsPrivateDelegateFactory::GetForBrowserContext(context_, true);
+  if (delegate) {
+    delegate->SendSavedPasswordsList();
+    delegate->SendPasswordExceptionsList();
   }
-  SendSavedPasswordListToListeners();
-  SendPasswordExceptionListToListeners();
-}
-
-void PasswordsPrivateEventRouter::OnListenerRemoved(
-    const EventListenerInfo& details) {
-  // Stop listening to events if there are no more listeners.
-  StartOrStopListeningForChanges();
 }
 
 void PasswordsPrivateEventRouter::OnSavedPasswordsListChanged(
@@ -86,7 +68,7 @@ void PasswordsPrivateEventRouter::OnSavedPasswordsListChanged(
 }
 
 void PasswordsPrivateEventRouter::SendSavedPasswordListToListeners() {
-  if (!cached_saved_password_parameters_.get() || ignore_updates_)
+  if (!cached_saved_password_parameters_.get())
     // If there is nothing to send, return early.
     return;
 
@@ -106,7 +88,7 @@ void PasswordsPrivateEventRouter::OnPasswordExceptionsListChanged(
 }
 
 void PasswordsPrivateEventRouter::SendPasswordExceptionListToListeners() {
-  if (!cached_password_exception_parameters_.get() || ignore_updates_)
+  if (!cached_password_exception_parameters_.get())
     // If there is nothing to send, return early.
     return;
 
@@ -136,31 +118,6 @@ void PasswordsPrivateEventRouter::OnPlaintextPasswordFetched(
   event_router_->BroadcastEvent(std::move(extension_event));
 }
 
-void PasswordsPrivateEventRouter::StartOrStopListeningForChanges() {
-  bool should_listen_for_saved_password_changes =
-      event_router_->HasEventListener(
-          api::passwords_private::OnSavedPasswordsListChanged::kEventName);
-  bool should_listen_for_password_exception_changes =
-      event_router_->HasEventListener(
-          api::passwords_private::OnPasswordExceptionsListChanged::kEventName);
-  bool should_listen_for_plaintext_password_retrieval =
-      event_router_->HasEventListener(
-          api::passwords_private::OnPlaintextPasswordRetrieved::kEventName);
-  bool should_listen = should_listen_for_saved_password_changes ||
-      should_listen_for_password_exception_changes ||
-      should_listen_for_plaintext_password_retrieval;
-
-  PasswordsPrivateDelegate* delegate =
-      PasswordsPrivateDelegateFactory::GetForBrowserContext(context_,
-                                                            true /* create */);
-  if (should_listen && !listening_)
-    delegate->AddObserver(this);
-  else if (!should_listen && listening_)
-    delegate->RemoveObserver(this);
-
-  listening_ = should_listen;
-}
-
 PasswordsPrivateEventRouter* PasswordsPrivateEventRouter::Create(
     content::BrowserContext* context) {
   return new PasswordsPrivateEventRouter(context);