Revert "cros: Move most event/widget handling logic out of LoginBubble"

This reverts commit a61287973e8f4522ed673ac1a77de0dc56eb1bc8.

Reason for revert: Suspect Failure single_process_mash_ash_unittests Failure ash_unittests:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/linux-chromeos-rel/16943
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8927839167159249024/+/steps/single_process_mash_ash_unittests/0/logs/LoginExpandedPublicAccountViewTest.ChangeMenuSelection/0
---
[ RUN      ] LoginExpandedPublicAccountViewTest.ChangeMenuSelection
Received signal 11 SEGV_MAPERR ffffe03f000008fe
#0 0x5631a3caedbf base::debug::StackTrace::StackTrace()
#1 0x5631a3cae941 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7faa9920f330 <unknown>
#3 0x5631a3aafbbf ash::LoginBubble::~LoginBubble()
#4 0x5631a3ab806c ash::RightPaneView::~RightPaneView()
#5 0x5631a3ab810e ash::RightPaneView::~RightPaneView()
#6 0x5631a40385d4 views::View::~View()
#7 0x5631a3ab6df9 ash::LoginExpandedPublicAccountView::~LoginExpandedPublicAccountView()
#8 0x5631a40385d4 views::View::~View()
#9 0x5631a300afce ash::(anonymous namespace)::DragTestView::~DragTestView()
#10 0x5631a4039b42 views::View::DoRemoveChildView()
#11 0x5631a403a175 views::View::RemoveAllChildViews()
#12 0x5631a4043b81 views::internal::RootView::~RootView()
#13 0x5631a400ef0e views::MenuHostRootView::~MenuHostRootView()
#14 0x5631a404615f views::Widget::~Widget()
#15 0x5631a34d645e exo::(anonymous namespace)::ShellSurfaceWidget::~ShellSurfaceWidget()
#16 0x5631a30c36f0 ash::LoginTestBase::TearDown()

Original change's description:
> cros: Move most event/widget handling logic out of LoginBubble
> 
> Changes made:
> - Move the (keyboard/click/tap) event handling logic into a
>   LoginBubbleHandler class.
> - Move the widget handling into LoginBaseBubbleView itself
> 
> Bug: 912658
> Change-Id: Ia1a9bf4b8d847ef74ef1716e73dfe1b16b8d19b2
> Reviewed-on: https://chromium-review.googlesource.com/c/1366516
> Commit-Queue: Quan Nguyen <qnnguyen@chromium.org>
> Reviewed-by: Jacob Dufault <jdufault@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#614544}

TBR=jdufault@chromium.org,qnnguyen@chromium.org

Change-Id: Ia9b9059f24f6aa6a8551c5c6bc5c76caafe592df
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 912658
Reviewed-on: https://chromium-review.googlesource.com/c/1367070
Reviewed-by: Takashi Sakamoto <tasak@google.com>
Commit-Queue: Takashi Sakamoto <tasak@google.com>
Cr-Commit-Position: refs/heads/master@{#614579}
4 files changed