Add --keyboard-usability-test flag and always show keyboard unless manually hide

ui/keyboard/keyboard_controller.cc

Index: ui/keyboard/keyboard_controller.cc
diff --git a/ui/keyboard/keyboard_controller.cc b/ui/keyboard/keyboard_controller.cc
index 313bc04f0cd77a1df96babfe2e17b852f3f513d2..94eced34866db97af6960bbf6b75dcb80bd5cdb7 100644
--- a/ui/keyboard/keyboard_controller.cc
+++ b/ui/keyboard/keyboard_controller.cc
@@ -5,6 +5,7 @@
 #include "ui/keyboard/keyboard_controller.h"
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
@@ -18,6 +19,7 @@
 #include "ui/gfx/skia_util.h"
 #include "ui/keyboard/keyboard_controller_observer.h"
 #include "ui/keyboard/keyboard_controller_proxy.h"
+#include "ui/keyboard/keyboard_switches.h"
 #include "ui/keyboard/keyboard_util.h"
 
 namespace {
@@ -151,6 +153,11 @@ aura::Window* KeyboardController::GetContainerWindow() {
 }
 
 void KeyboardController::HideKeyboard(HideReason reason) {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(

[kevers, 2013/10/23 11:37:39]

I think this belongs right before the "keyboard_visible_ = false;
...PostDelayedTask" below.  Otherwise, the keyboard could report the wrong state
of its visibility and an artificially high stat for showing the keyboard. 
Alternatively, you could reset the keyboard_visible_ to true here before the
early return.

[sadrul, 2013/10/23 14:01:49]

Agree. It would probably be better to just set |should_show| to true when this
flag is set?

[bshe, 2013/10/23 17:08:43]

I agree with the above and have moved it before the "keyboard_visible_ = false".
There is one issue though. We depend on focus on a text input box to trigger
keyboard show. Ideally, we should not depending on it.

In that sense,  set |should_show| to true when the flag is on seems like the
right approach. But it looks like Chrome crashes before login if we directly set
|should_show| to true. And the reason seems because we try to get default
profile when keyboard initialize. But it is too early to request profile at that
point. I moved the keyboard initialization to PostProfileInit. It failed again
because TextInputClient is null at that point. Anyway, it looks like it is not
trivial to set |should_show| to true. Added a TODO and will deal with it in a
separate CL.

On 2013/10/23 14:01:49, sadrul wrote:

+      switches::kKeyboardUsabilityTest) && reason == HIDE_REASON_AUTOMATIC) {
+    return;
+  }
+
   keyboard_visible_ = false;
 
   keyboard::LogKeyboardControlEvent(