Remove the Views bubble double widget hack.

Views bubbles had a hack to use two separate widgets.
The border widget supported per-pixel alpha for edge images.
The content widget supported native windows textfields, etc.
This isn't needed after win textfield removal in r235220.

Remove BubbleBorderDelegate and the border widget code.
Remove BubbleDelegateView::GetBubbleClientBounds
Remove BubbleBorder::client_bounds and usage.
(was used to clip intersecting widget area during fade)

BUG=131660
TEST=No visual difference, no regressions (I tested that bubbles still work on a local non-Aura Win build too).
R=sky@chromium.org

Review URL: https://codereview.chromium.org/73533002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235715 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235715
Safebrowsing aura linux_redux compile fixes.

BUG=319217

Review URL: https://codereview.chromium.org/73573002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235716 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235716