Change system settings based on when mouse/touchpad is connected/disconnected.

chrome/browser/ui/webui/options2/chromeos/system_options_handler.cc

Index: chrome/browser/ui/webui/options2/chromeos/system_options_handler.cc
===================================================================
--- chrome/browser/ui/webui/options2/chromeos/system_options_handler.cc	(revision 115229)
+++ chrome/browser/ui/webui/options2/chromeos/system_options_handler.cc	(working copy)
@@ -44,12 +44,19 @@
 void TouchpadExistsFileThread(bool* exists) {
   *exists = chromeos::system::touchpad_settings::TouchpadExists();
 }
+
+void MouseExistsFileThread(bool* exists) {
+  *exists = chromeos::system::mouse_settings::MouseExists();
 }
 
+}  // namespace
+
 SystemOptionsHandler::SystemOptionsHandler() {
 }
 
 SystemOptionsHandler::~SystemOptionsHandler() {
+  chromeos::XInputHierarchyChangedEventListener::GetInstance()
+      ->RemoveObserver(this);
 }
 
 void SystemOptionsHandler::GetLocalizedValues(
@@ -126,19 +133,37 @@
   web_ui_->CallJavascriptFunction(
       "options.SystemOptions.SetAccessibilityCheckboxState", checked);
 
+  chromeos::XInputHierarchyChangedEventListener::GetInstance()
+      ->AddObserver(this);
+  DeviceChanged();
+}
+
+void SystemOptionsHandler::CheckTouchpadExists() {
   bool* exists = new bool;
   BrowserThread::PostTaskAndReply(BrowserThread::FILE, FROM_HERE,
       base::Bind(&TouchpadExistsFileThread, exists),
       base::Bind(&SystemOptionsHandler::TouchpadExists, AsWeakPtr(), exists));
 }
 
+void SystemOptionsHandler::CheckMouseExists() {
+  bool* exists = new bool;
+  BrowserThread::PostTaskAndReply(BrowserThread::FILE, FROM_HERE,
+      base::Bind(&MouseExistsFileThread, exists),
+      base::Bind(&SystemOptionsHandler::MouseExists, AsWeakPtr(), exists));
+}
+
 void SystemOptionsHandler::TouchpadExists(bool* exists) {
-  if (*exists)
-    web_ui_->CallJavascriptFunction(
-        "options.SystemOptions.showTouchpadControls");
+  web_ui_->CallJavascriptFunction("options.SystemOptions.showTouchpadControls",
+                                  base::FundamentalValue(*exists));
   delete exists;
 }
 
+void SystemOptionsHandler::MouseExists(bool* exists) {
+  web_ui_->CallJavascriptFunction("options.SystemOptions.showMouseControls",
+                                  base::FundamentalValue(*exists));
+  delete exists;
+}
+
 void SystemOptionsHandler::RegisterMessages() {
   DCHECK(web_ui_);
   web_ui_->RegisterMessageCallback("accessibilityChange",
@@ -153,6 +178,11 @@
                  base::Unretained(this)));
 }
 
+void SystemOptionsHandler::DeviceChanged() {
+  CheckMouseExists();
+  CheckTouchpadExists();
+}
+
 void SystemOptionsHandler::AccessibilityChangeCallback(const ListValue* args) {
   std::string checked_str;
   args->GetString(0, &checked_str);