Remove more keyboard usability related code

BUG=414766

Review URL: https://codereview.chromium.org/587243004

Cr-Commit-Position: refs/heads/master@{#296250}

ash/display/display_controller.cc

@@ -248,8 +248,6 @@ DisplayController::~DisplayController() {
 }
 
 void DisplayController::Start() {
-  // Created here so that Shell has finished being created. Adds itself
-  // as a ShellObserver.
   Shell::GetScreen()->AddObserver(this);
   Shell::GetInstance()->display_manager()->set_delegate(this);
 }

ash/root_window_controller.cc

@@ -274,13 +274,6 @@ void RootWindowController::CreateForSecondaryDisplay(AshWindowTreeHost* host) {
   controller->Init(RootWindowController::SECONDARY, false /* first run */);
 }
 
-void RootWindowController::CreateForVirtualKeyboardDisplay(
-    AshWindowTreeHost* host) {
-  RootWindowController* controller = new RootWindowController(host);
-  controller->Init(RootWindowController::VIRTUAL_KEYBOARD,
-                   false /* first run */);
-}
-
 // static
 RootWindowController* RootWindowController::ForShelf(
     const aura::Window* window) {
@@ -719,14 +712,6 @@ void RootWindowController::Init(RootWindowType root_window_type,
   ash_host_->AsWindowTreeHost()->SetCursor(ui::kCursorPointer);
   CreateContainersInRootWindow(root_window);
 
-  if (root_window_type == VIRTUAL_KEYBOARD) {
-    aura::Window* virtual_keyboard_parent_container = GetContainer(
-        kShellWindowId_VirtualKeyboardParentContainer);
-    virtual_keyboard_parent_container->SetBounds(root_window->bounds());
-    shell->InitKeyboard();
-    return;
-  }
-
   CreateSystemBackground(first_run_after_boot);
 
   InitLayoutManagers();

ash/root_window_controller.h

@@ -242,8 +242,7 @@ class ASH_EXPORT RootWindowController : public ShellObserver {
   explicit RootWindowController(AshWindowTreeHost* host);
   enum RootWindowType {
     PRIMARY,
-    SECONDARY,
-    VIRTUAL_KEYBOARD
+    SECONDARY
   };
 
   // Initializes the RootWindowController.  |is_primary| is true if