Revert of Move DefaultActivationClient to wm/core

Revert of Move DefaultActivationClient to wm/core (https://codereview.chromium.org/250113002/)

Reason for revert:
views_unittest TooltipController test failures
views_unittests views_unittests 4 disabled 10 flaky failed 10 ( 9 secs )
stdio
Capture
CloseOnCaptureLost
DontShowEmptyTooltips
EnableOrDisableTooltips
HideOnExit
ReshowOnClickAfterEnterExit
TooltipHidesOnKeyPressAndStaysHiddenUntilChange
TooltipHidesOnTimeoutAndStaysHiddenUntilChange
TooltipsInMultipleViews
ViewTooltip


TooltipControllerTest.ViewTooltip (run #2):
[ RUN      ] TooltipControllerTest.ViewTooltip
Xlib:  extension "RANDR" missing on display ":9".
Received signal 11 SEGV_MAPERR 000000000000
#0 0x000000a88e4e base::debug::StackTrace::StackTrace()
#1 0x000000a89068 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7f9474270cb0 \u003Cunknown>
#3 0x000000736b83 views::NativeWidgetAura::Activate()
#4 0x000000737508 views::NativeWidgetAura::ShowWithWindowState()
#5 0x000000738acb views::Widget::Show()
#6 0x00000052cb09 views::corewm::test::(anonymous namespace)::CreateWidget()
#7 0x00000052d397 views::corewm::test::TooltipControllerTest::SetUp()
#8 0x00000065a16a testing::Test::Run().

Original issue's description:
> Move DefaultActivationClient to wm/core
> 
> Several tests are using AuraTestHelper and were relying on it to set up the DefaultActivationClient, so I had to have them instantiate the DAC directly after calling SetUp() on the helper. I also had to make the DAC delete itself after the root window it's bound to is destroyed.
> 
> R=sky@chromium.org
> http://crbug.com/308710
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266616
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266975

TBR=sky@chromium.org,ben@chromium.org
NOTREECHECKS=true
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=267001

[robliao, 2014-04-30 00:09:22]

Created Revert of Move DefaultActivationClient to wm/core

[robliao, 2014-04-30 00:09:45]

The CQ bit was checked by robliao@chromium.org

[commit-bot: I haz the power, 2014-04-30 00:11:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/robliao@chromium.org/261553002/1

[commit-bot: I haz the power, 2014-04-30 00:14:08]

Change committed as 267001