Address views session crashed bubble style nits.

Address views session crashed bubble style nits.

Use the built-in bubble title and close button views.
Use the bubble's title insets for the other views.
Use BookmarkSyncPromoView colors for the UMA promo.
Use views layout constants for the spacing values.
Use default label/checkbox/bubble colors, not hard-coded.
(black/off-white + supports inversion for accessibility)
Fix the UMA promo separator line (wasn't fully extended).

Inline some BrowserRemovalObserver function implementations.
Other misc. code cleanup. See before/after pics on the bug.

BUG=384123
TEST=Session crashes bubble looks good, works well.
R=yiyaoliu@chromium.org,sky@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278228

[msw, 2014-06-18 01:51:45]

Please take a look and see the pics on the bug; thanks!
This CL makes the bubble more similar to the bookmark bubble.

I'll probably do a more widespread bubble style cleanup soon:
1) Make a common client view for buttons/promos, like dialog.
2) Update other bubbles using odd titles and close buttons.

[yao, 2014-06-18 14:44:27]

lgtm

Hi Mike, 

Thanks a lot for doing this. There's many thing I didn't know/realize & learnt a
lot from your CL. Thanks!

Yiyao

[msw, 2014-06-18 15:49:49]

On 2014/06/18 14:44:27, yao wrote:
> Hi Mike, 
> 
> Thanks a lot for doing this. There's many thing I didn't know/realize & learnt
a
> lot from your CL. Thanks!
> 
> Yiyao

You're welcome; I'm glad to be of help.
Hey Scott, please take a look; thanks!

[sky, 2014-06-18 17:14:09]

LGTM

[msw, 2014-06-18 17:33:51]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2014-06-18 17:35:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/msw@chromium.org/331353002/40001

[commit-bot: I haz the power, 2014-06-19 01:33:49]

Change committed as 278228