Add a browser-test for the keyboard widget.

chrome/browser/ui/touch/keyboard/keyboard_manager.cc

Index: chrome/browser/ui/touch/keyboard/keyboard_manager.cc
diff --git a/chrome/browser/ui/touch/keyboard/keyboard_manager.cc b/chrome/browser/ui/touch/keyboard/keyboard_manager.cc
index c21f20522b46f2e308063ddc7c36b8f4e817b3d9..c5442918d3c06018a2c6797b4ac4e913a1217c3f 100644
--- a/chrome/browser/ui/touch/keyboard/keyboard_manager.cc
+++ b/chrome/browser/ui/touch/keyboard/keyboard_manager.cc
@@ -146,10 +146,22 @@ void KeyboardManager::ShowKeyboardForWidget(views::Widget* widget) {
 
   MoveToTop();
   Show();
+
+  bool visible = true;
+  NotificationService::current()->Notify(
+      NotificationType::KEYBOARD_VISIBILITY_CHANGED,
+      Source<KeyboardManager>(this),
+      Details<bool>(&visible));
 }
 
 void KeyboardManager::Hide() {
   animation_->Hide();
+
+  bool visible = false;
+  NotificationService::current()->Notify(
+      NotificationType::KEYBOARD_VISIBILITY_CHANGED,
+      Source<KeyboardManager>(this),
+      Details<bool>(&visible));
 }
 
 bool KeyboardManager::OnKeyEvent(const views::KeyEvent& event) {