Revert of Store and restore view focus in OnWindowFocused.

Revert of Store and restore view focus in OnWindowFocused. (https://codereview.chromium.org/282223002/)

Reason for revert:
ConstrainedWindowViewTest.ClosesOnEscape introduced in this patch fails on XP: http://build.chromium.org/p/chromium.win/builders/XP%20Tests%20%281%29/builds/31239/steps/interactive_ui_tests/logs/stdio

Original issue's description:
> Store and restore view focus in OnWindowFocused.
> 
> Mimic [Desktop]NativeWidgetAura::OnWindowActivated.
> Simplify OnNativeBlur calls and OnNative[Blur|Focus] impls.
> (View focus changes update the TextInputClient as needed)
> Rewrite and enable related ConstrainedWindowViewTests.
> 
> Print GetLastError() in SendInput() error case for tests.
> (key presses get 5/ERROR_ACCESS_DENIED on locked desktops?)
> 
> BUG=368691, 170331, 177482, 163931
> TEST=Automated tests; the focused Views change as expected between the browser, web contents, and web content modal dialogs (print preview, collected cookies, etc.).
> R=sky@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271249

TBR=sky@chromium.org,msw@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=368691, 170331, 177482, 163931
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271281

[ckocagil, 2014-05-18 13:50:38]

Created Revert of Store and restore view focus in OnWindowFocused.

[commit-bot: I haz the power, 2014-05-18 13:50:44]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ckocagil@chromium.org/289283003/1

[commit-bot: I haz the power, 2014-05-18 13:51:43]

Change committed as 271281

[msw, 2014-05-18 15:52:42]

On 2014/05/18 13:51:43, I haz the power (commit-bot) wrote:
> Change committed as 271281

Dang, lgtm.