Reland Propagate OnNativeWidgetMove to delegate/observers, etc.

Reland Propagate OnNativeWidgetMove to delegate/observers, etc.
Continuation of reverted CL http://codereview.chromium.org/10021029
The original CL was reverted due to a naming conflict between:
WidgetDelegate::OnWidgetMove and Widget::Observer::OnWidgetMove.
I renamed the new Observer method to OnWidgetMoved.

Original description:
Propagate OnNativeWidgetMove to delegate/observers, etc.
NativeWidget[Aura|Win] calls new Widget::OnNativeWidgetMove.
Widgets alert delegates and new Widget::Observer::OnWidgetMove.

TabDragController2: consume new observer method, simplify.
Nix BrowserWindowMoveObserver; use Widget::Observer instead.
Replace move_loop_browser_view_ with move_loop_widget.
Replace GetAttachedBrowserView with GetAttachedBrowserWidget.

BubbleDelegateView: consume new observer method.
Make bubbles move with their anchor_view's Widgets.
SchedulePaint on BubbleFrameView when mirroring its arrow.

BUG=105151, 116336
TEST=Bubbles can move with the browser window (inspecting extension popups, etc.); no Ash / --enable-tab-browser-dragging regressions.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=133057

[msw, 2012-04-19 18:53:25]

Hey Ben, please review this minor CL update; thanks!

[Ben Goodger (Google), 2012-04-19 19:03:02]

lgtm

[commit-bot: I haz the power, 2012-04-19 19:07:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/msw@chromium.org/10025039/6001

[commit-bot: I haz the power, 2012-04-19 21:17:58]

Change committed as 133057