Revert of Remove deprecated extension notification from ProcessManager.

extensions/browser/process_manager_unittest.cc

Index: extensions/browser/process_manager_unittest.cc
diff --git a/extensions/browser/process_manager_unittest.cc b/extensions/browser/process_manager_unittest.cc
index 957e3a2cfa9cd77be95db8b451b0535b91c3cf09..e04b0d32eb18ed1ab8b69e238d031d51c0e5df3b 100644
--- a/extensions/browser/process_manager_unittest.cc
+++ b/extensions/browser/process_manager_unittest.cc
@@ -111,6 +111,13 @@
                            extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
                            original_context()));
   EXPECT_TRUE(IsRegistered(manager1.get(),
+                           extensions::NOTIFICATION_EXTENSION_LOADED_DEPRECATED,
+                           original_context()));
+  EXPECT_TRUE(
+      IsRegistered(manager1.get(),
+                   extensions::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
+                   original_context()));
+  EXPECT_TRUE(IsRegistered(manager1.get(),
                            extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED,
                            original_context()));
 
@@ -123,6 +130,11 @@
 
   EXPECT_EQ(incognito_context(), manager2->GetBrowserContext());
   EXPECT_EQ(0u, manager2->background_hosts().size());
+
+  // Some notifications are observed for the original context.
+  EXPECT_TRUE(IsRegistered(manager2.get(),
+                           extensions::NOTIFICATION_EXTENSION_LOADED_DEPRECATED,
+                           original_context()));
 
   // Some notifications are observed for the incognito context.
   EXPECT_TRUE(IsRegistered(manager2.get(),