Notifies the IME extension for IME ready with onActivate/onFocus events at start.

chrome/browser/extensions/api/input_ime/input_ime_api.cc

Index: chrome/browser/extensions/api/input_ime/input_ime_api.cc
diff --git a/chrome/browser/extensions/api/input_ime/input_ime_api.cc b/chrome/browser/extensions/api/input_ime/input_ime_api.cc
index f45589e9b44d1a0ab5001465cb87d929be16f8ef..e3496644fd97b90c2514798c77a3114f013e0718 100644
--- a/chrome/browser/extensions/api/input_ime/input_ime_api.cc
+++ b/chrome/browser/extensions/api/input_ime/input_ime_api.cc
@@ -374,6 +374,21 @@ InputImeAPI::~InputImeAPI() {
   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
+void InputImeAPI::OnListenerAdded(const EventListenerInfo& details) {
+  if (!details.browser_context)
+    return;
+  InputImeEventRouter* event_router =
+      GetInputImeEventRouter(Profile::FromBrowserContext(
+          Profile::FromBrowserContext(details.browser_context)));
+  InputMethodEngineBase* engine =
+      event_router ? event_router->GetActiveEngine(details.extension_id)
+                   : nullptr;
+
+  // Notifies the IME extension for IME ready with onActivate/onFocus events.
+  if (engine)
+    engine->Enable(engine->GetActiveComponentId());
+}
+
 static base::LazyInstance<BrowserContextKeyedAPIFactory<InputImeAPI> >
     g_factory = LAZY_INSTANCE_INITIALIZER;