[Passwords] Introduce PasswordStore::::Observer::OnLoginsChangedIn()

It's similar to PasswordStore::::Observer::OnLoginsChanged() but
captures the originating store too.

Bug: 1108422
Change-Id: I30ce80beec9d7a38bd4d148fe80b8efba722437d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2362610
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799599}

components/password_manager/core/browser/password_store.cc

@@ -83,6 +83,12 @@ void CloseTraceAndCallBack(
 
 }  // namespace
 
+void PasswordStore::Observer::OnLoginsChangedIn(
+    PasswordStore* store,
+    const PasswordStoreChangeList& changes) {
+  OnLoginsChanged(changes);
+}
+
 #if defined(SYNC_PASSWORD_REUSE_DETECTION_ENABLED)
 PasswordStore::CheckReuseRequest::CheckReuseRequest(
     PasswordReuseDetectorConsumer* consumer)
@@ -731,7 +737,8 @@ void PasswordStore::NotifyLoginsChanged(
     const PasswordStoreChangeList& changes) {
   DCHECK(background_task_runner_->RunsTasksInCurrentSequence());
   if (!changes.empty()) {
-    observers_->Notify(FROM_HERE, &Observer::OnLoginsChanged, changes);
+    observers_->Notify(FROM_HERE, &Observer::OnLoginsChangedIn,
+                       base::RetainedRef(this), changes);
     if (sync_bridge_)
       sync_bridge_->ActOnPasswordStoreChanges(changes);
 

components/password_manager/core/browser/password_store.h

@@ -89,6 +89,14 @@ class PasswordStore : protected PasswordStoreSync,
     // the UI thread.
     virtual void OnLoginsChanged(const PasswordStoreChangeList& changes) = 0;
 
+    // Like OnLoginsChanged(), but also receives the originating PasswordStore
+    // as a parameter. This is useful for observers that observe changes in both
+    // the profile-scoped and the account-scoped store. The default
+    // implementation simply calls OnLoginsChanged(), so observers that don't
+    // care about the store can just ignore this.
+    virtual void OnLoginsChangedIn(PasswordStore* store,
+                                   const PasswordStoreChangeList& changes);
+
    protected:
     virtual ~Observer() = default;
   };