[IME] Releases key events to default handler if no handler in the active IME extension.

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/input_ime/input_ime_api.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/input_method/input_method_engine.h"
@@ skipping 146 matching lines @@
                              args.Pass());
   }
 
   virtual void OnKeyEvent(
       const std::string& engine_id,
       const InputMethodEngineInterface::KeyboardEvent& event,
       chromeos::input_method::KeyEventHandle* key_data) OVERRIDE {
     if (profile_ == NULL || extension_id_.empty())
       return;
 
+    if (!extensions::ExtensionSystem::Get(profile_)

[Hiro Komatsu, 2014/02/13 09:39:50]

Please add a comment above this block.

[Shu Chen, 2014/02/13 13:13:41]

Done.

+             ->event_router()
+             ->ExtensionHasEventListener(extension_id_,
+                                         input_ime::OnKeyEvent::kEventName)) {
+      InputMethodEngineInterface* engine =

[Hiro Komatsu, 2014/02/13 09:39:50]

How about calling InputImeEventRouter::OnKeyEventHandled?

[Shu Chen, 2014/02/13 13:13:41]

I had thought about it. To use InputImeEventRouter::OnKeyEventHandled(), the
below InputImeEventRouter::AddRequest() should be called. InputImeEventRouter
maintains an internal map to retrieve the key_data from the request_id.
For performance consideration, I would prefer to return here sooner rather than
reuse InputImeEventRouter.

On 2014/02/13 09:39:50, Hiro Komatsu wrote:

[Hiro Komatsu, 2014/02/14 05:04:06]

I see the point.  Since AddRequest is not so expensive and this speed does not
matter for user's typing, I prefer using the existing function.

+          extensions::InputImeEventRouter::GetInstance()->GetActiveEngine(
+              extension_id_);
+      if (engine)
+        engine->KeyEventDone(key_data, false);
+      return;
+    }
+
     std::string request_id =
         extensions::InputImeEventRouter::GetInstance()->AddRequest(engine_id,
                                                                    key_data);
 
     input_ime::KeyboardEvent key_data_value;
     key_data_value.type = input_ime::KeyboardEvent::ParseType(event.type);
     key_data_value.request_id = request_id;
     key_data_value.key = event.key;
     key_data_value.code = event.code;
     key_data_value.alt_key.reset(new bool(event.alt_key));
@@ skipping 630 matching lines @@
     if (input_components->size() > 0)
       input_ime_event_router()->UnregisterAllImes(profile_, extension->id());
   }
 }
 
 InputImeEventRouter* InputImeAPI::input_ime_event_router() {
   return InputImeEventRouter::GetInstance();
 }
 
 }  // namespace extensions