Check --enable-virtual-keyboard flag when sending keyboard type to a client.

--enable-virtual-keyboard flag is used to force-enable VK for testing.
This CL makes exo::Keyboard send the flag information to a wayland client.

Bug: 852351
Test: manual - enable the flag and check VK is enabled on ARC++ apps
Change-Id: I0ca7c895aa960ddbfa2118bcf2c14d506a184f19
Reviewed-on: https://chromium-review.googlesource.com/c/1454168Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Yuichiro Hanada <yhanada@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629420}

components/exo/keyboard.cc

@@ -116,7 +116,10 @@ bool ConsumedByIme(Surface* focus, const ui::KeyEvent* event) {
 
 bool IsVirtualKeyboardEnabled() {
   return keyboard::GetAccessibilityKeyboardEnabled() ||
-         keyboard::GetTouchKeyboardEnabled();
+         keyboard::GetTouchKeyboardEnabled() ||
+         (keyboard::KeyboardController::HasInstance() &&
+          keyboard::KeyboardController::Get()->IsEnableFlagSet(
+              keyboard::mojom::KeyboardEnableFlag::kCommandLineEnabled));
 }
 
 bool IsReservedAccelerator(const ui::KeyEvent* event) {