DRAFT: Add setKeyboardVisibility API.

Add setKeyboardVisibility API.

This allows the visibility of the API to be controlled directly from
extensions requesting the API, and allows the "hide keyboard" button to
be implemented.

BUG=236925

[bryeung, 2013-04-30 20:21:03]

Sadrul: this CL still has a couple of issues, but I'd like to get your take on
it if you have time.

Issues:
- hiding from JS seems janky (more details in the comments)
- hiding from the app-list causes the app-list to lose focus
- cannot re-summon by clicking on the same text field again

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_controll...
File ui/keyboard/keyboard_controller.cc (right):

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_controll...
ui/keyboard/keyboard_controller.cc:170: container_->Hide();
directly hiding the keyboard from JS seems to cause jank: the animation on the
button looks to still be in progress when the keyboard is shown again.  Any idea
what's going on with that?

[sadrul, 2013-05-14 06:23:19]

> - hiding from the app-list causes the app-list to lose focus

Perhaps because this causes the app-list window to move?

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_controll...
File ui/keyboard/keyboard_controller.cc (right):

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_controll...
ui/keyboard/keyboard_controller.cc:170: container_->Hide();
On 2013/04/30 20:21:03, bryeung wrote:
> directly hiding the keyboard from JS seems to cause jank: the animation on the
> button looks to still be in progress when the keyboard is shown again.  Any
idea
> what's going on with that?

Animation in the page itself should not be causing the window-hide to jank.
Something is probably doing bad things, but I can't think of what it might be.

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_ui_handl...
File ui/keyboard/keyboard_ui_handler.cc (right):

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_ui_handl...
ui/keyboard/keyboard_ui_handler.cc:30: "setKeyboardVisibility",
Will this be ever used to show the keyboard? i.e. will the keyboard JS be able
to show itself while it was hidden? If it does, what would be the target of the
key events (e.g. no view/window is currently focused, or if the focused
view/window does not accept text input etc.)?

https://codereview.chromium.org/14674004/diff/1/ui/keyboard/keyboard_ui_handl...
ui/keyboard/keyboard_ui_handler.cc:46: // TODO(sadrul): get the
KeyboardController without using the Shell
I can't think of a good way of doing this. One option would be to remove the
focus from the currently focused view/window, when the visibility is changing to
hidden.