Add virtual keyboard item into opt-in IME menu.

ash/common/system/chromeos/ime_menu/ime_menu_tray.cc

Index: ash/common/system/chromeos/ime_menu/ime_menu_tray.cc
diff --git a/ash/common/system/chromeos/ime_menu/ime_menu_tray.cc b/ash/common/system/chromeos/ime_menu/ime_menu_tray.cc
index 92423349d3f77378cda459cd1a10ffb70d3008b1..bbc93630ed182e57bde088cbc43dc61298cd5670 100644
--- a/ash/common/system/chromeos/ime_menu/ime_menu_tray.cc
+++ b/ash/common/system/chromeos/ime_menu/ime_menu_tray.cc
@@ -279,7 +279,8 @@ ImeMenuTray::ImeMenuTray(WmShelf* wm_shelf)
       label_(new ImeMenuLabel()),
       show_keyboard_(false),
       force_show_keyboard_(false),
-      should_block_shelf_auto_hide_(false) {
+      should_block_shelf_auto_hide_(false),
+      keyboard_suppressed_(false) {
   SetupLabelForTray(label_);
   tray_container()->AddChildView(label_);
   SetContentsBackground();
@@ -321,8 +322,8 @@ void ImeMenuTray::ShowImeMenuBubble() {
   }
 
   // Adds IME list to the bubble.
-  ime_list_view_ =
-      new ImeListView(nullptr, false, ImeListView::SHOW_SINGLE_IME);
+  ime_list_view_ = new ImeListView(nullptr, ShouldShowKeyboardToggle(),
+                                   ImeListView::SHOW_SINGLE_IME);
 
   uint32_t current_height = ime_list_view_->scroll_content()->height();
   const gfx::Range height_range = GetImeListViewRange();
@@ -406,6 +407,11 @@ bool ImeMenuTray::ShouldBlockShelfAutoHide() const {
   return should_block_shelf_auto_hide_;
 }
 
+bool ImeMenuTray::ShouldShowKeyboardToggle() const {
+  return keyboard_suppressed_ &&

[tdanderson, 2016/11/03 21:17:20]

I left the following comment in
https://chromiumcodereview.appspot.com/2469663002/:

"I went into non-MD mode on canary, plugged in an external keyboard, and entered
touchview (maximize mode). When I go into the IME detailed view I see a "disable
on-screen keyboard" button, and when I tap it it turns into an "enable on-screen
keyboard" button. So the toggle row needs to be shown regardless of whether the
toggle state is on or off."

With that said, I don't think you are doing the right thing in this CL. To avoid
any confusion, let's iterate on and land
https://chromiumcodereview.appspot.com/2469663002/ first and then we can come
back to this CL.

[Azure Wei, 2016/11/20 08:56:23]

The method return true when the 'smart deploy toggle' should be shown:
If the user is in TouchView (virtual keyboard should be automatically deployed
if IsVirtualKeyboardEnabled() is false) and an external keyboard attached
(keyboard_suppressed_ is true). 
If the keyboard toggle is shown, turn on or off the toggle should not change the
returned value of this method.

+         !WmShell::Get()->accessibility_delegate()->IsVirtualKeyboardEnabled();
+}
+
 void ImeMenuTray::SetShelfAlignment(ShelfAlignment alignment) {
   TrayBackgroundView::SetShelfAlignment(alignment);
   if (!MaterialDesignController::IsShelfMaterial())
@@ -534,6 +540,12 @@ void ImeMenuTray::OnKeyboardHidden() {
   force_show_keyboard_ = false;
 }
 
+void ImeMenuTray::OnKeyboardSuppressionChanged(bool suppressed) {
+  if (suppressed != keyboard_suppressed_ && bubble_)
+    HideImeMenuBubble();
+  keyboard_suppressed_ = suppressed;
+}
+
 void ImeMenuTray::UpdateTrayLabel() {
   WmShell::Get()->system_tray_delegate()->GetCurrentIME(&current_ime_);