Reduce CPU usage for input method switching.

chrome/browser/chromeos/status/input_method_menu.cc

 // Copyright (c) 2010 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/chromeos/status/input_method_menu.h"
 
 #include <string>
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ skipping 360 matching lines @@
 
 void InputMethodMenu::RunMenu(
     views::View* unused_source, const gfx::Point& pt) {
   PrepareForMenuOpen();
   input_method_menu_.RunMenuAt(pt, views::Menu2::ALIGN_TOPRIGHT);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // InputMethodLibrary::Observer implementation:
 
-void InputMethodMenu::InputMethodChanged(InputMethodLibrary* obj) {
+void InputMethodMenu::InputMethodChanged(
+    InputMethodLibrary* obj,
+    const InputMethodDescriptor& previous_input_method,
+    const InputMethodDescriptor& current_input_method,
+    size_t num_active_input_methods) {
   UserMetrics::RecordAction(
       UserMetricsAction("LanguageMenuButton_InputMethodChanged"));
+  UpdateUIFromInputMethod(current_input_method, num_active_input_methods);
+}
 
-  const InputMethodDescriptor& previous_input_method =
-      obj->previous_input_method();
-  const InputMethodDescriptor& current_input_method =
-      obj->current_input_method();
-  UpdateUIFromInputMethod(current_input_method);
-  // Update Chrome prefs as well.
+void InputMethodMenu::PreferenceUpdateNeeded(
+    InputMethodLibrary* obj,
+    const InputMethodDescriptor& previous_input_method,
+    const InputMethodDescriptor& current_input_method) {
   if (is_browser_mode_) {
     if (pref_service_) {  // make sure we're not in unit tests.
       // Sometimes (e.g. initial boot) |previous_input_method.id| is empty.
       previous_input_method_pref_.SetValue(previous_input_method.id);
       current_input_method_pref_.SetValue(current_input_method.id);
     }
   } else {
     // We're in the login screen (i.e. not in the normal browser mode nor screen
     // locker mode). If a user has already logged in, we should not update the
     // local state since a profile for the user might be loaded before the
@@ skipping 10 matching lines @@
   UserMetrics::RecordAction(UserMetricsAction("LanguageMenuButton_Open"));
   input_method_descriptors_.reset(CrosLibrary::Get()->GetInputMethodLibrary()->
                                   GetActiveInputMethods());
   RebuildModel();
   input_method_menu_.Rebuild();
   if (minimum_input_method_menu_width_ > 0) {
     input_method_menu_.SetMinimumWidth(minimum_input_method_menu_width_);
   }
 }
 
-void InputMethodMenu::ActiveInputMethodsChanged(InputMethodLibrary* obj) {
+void InputMethodMenu::ActiveInputMethodsChanged(
+    InputMethodLibrary* obj,
+    const InputMethodDescriptor& current_input_method,
+    size_t num_active_input_methods) {
   // Update the icon if active input methods are changed. See also
-  // comments in UpdateUI()
-  UpdateUIFromInputMethod(obj->current_input_method());
-}
-
-void InputMethodMenu::ImePropertiesChanged(InputMethodLibrary* obj) {
+  // comments in UpdateUI() in input_method_menu_button.cc.
+  UpdateUIFromInputMethod(current_input_method, num_active_input_methods);
 }
 
 void InputMethodMenu::UpdateUIFromInputMethod(
-    const InputMethodDescriptor& input_method) {
+    const InputMethodDescriptor& input_method,
+    size_t num_active_input_methods) {
   const std::wstring name = GetTextForIndicator(input_method);
   const std::wstring tooltip = GetTextForMenu(input_method);
-  UpdateUI(name, tooltip);
+  UpdateUI(input_method.id, name, tooltip, num_active_input_methods);
 }
 
 void InputMethodMenu::RebuildModel() {
   model_.reset(new menus::SimpleMenuModel(NULL));
   string16 dummy_label = UTF8ToUTF16("");
   // Indicates if separator's needed before each section.
   bool need_separator = false;
 
   if (!input_method_descriptors_->empty()) {
     // We "abuse" the command_id and group_id arguments of AddRadioItem method.
@@ skipping 161 matching lines @@
     logged_in_ = true;
   }
 }
 
 void InputMethodMenu::SetMinimumWidth(int width) {
   // On the OOBE network selection screen, fixed width menu would be preferable.
   minimum_input_method_menu_width_ = width;
 }
 
 }  // namespace chromeos