Redo how AppBannerInfoBars are created and stored

Redo how AppBannerInfoBars are created and stored

* AppBannerManager will now keep a pointer to the
  AppBannerInfoBar that gets created for it, which
  will allow it to update the UI as needed.

* Gets rid of AppBannerInfoBarDelegate; that design
  pattern doesn't make much sense even for ConfirmInfoBars.

* AppBannerManager becomes an EmptyTabObserver.

- Breaks native app promos: they won't show up until
  a follow up CL lands. Functions related to the
  AppBannerView will be removed soon.

BUG=453170
Committed: https://crrev.com/73cb4e12164e4d0023db17b91241b0e77f5d21fd
Cr-Commit-Position: refs/heads/master@{#314870}

[gone, 2015-02-05 18:53:10]

dfalcantara@chromium.org changed reviewers:
+ newt@chromium.org, tedchoc@chromium.org

[newt (away), 2015-02-05 19:21:09]

lgtm

https://codereview.chromium.org/901203003/diff/20001/chrome/browser/android/b...
File chrome/browser/android/banners/app_banner_manager.cc (right):

https://codereview.chromium.org/901203003/diff/20001/chrome/browser/android/b...
chrome/browser/android/banners/app_banner_manager.cc:85: bool
AppBannerManager::OnButtonClicked() const {
Why does this always return true? Is this return value even needed then?

[gone, 2015-02-05 19:24:19]

https://codereview.chromium.org/901203003/diff/20001/chrome/browser/android/b...
File chrome/browser/android/banners/app_banner_manager.cc (right):

https://codereview.chromium.org/901203003/diff/20001/chrome/browser/android/b...
chrome/browser/android/banners/app_banner_manager.cc:85: bool
AppBannerManager::OnButtonClicked() const {
On 2015/02/05 19:21:09, newt wrote:
> Why does this always return true? Is this return value even needed then?

Follow up CL returns false when installing native apps to prevent the infobar
from going away.

[gone, 2015-02-05 19:24:28]

The CQ bit was checked by dfalcantara@chromium.org

[commit-bot: I haz the power, 2015-02-05 19:25:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/901203003/20001

[gone, 2015-02-05 19:27:42]

The CQ bit was unchecked by dfalcantara@chromium.org

[gone, 2015-02-05 19:34:55]

New patchsets have been uploaded after l-g-t-m from newt@chromium.org

[gone, 2015-02-05 19:36:38]

The CQ bit was checked by dfalcantara@chromium.org

[commit-bot: I haz the power, 2015-02-05 19:38:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/901203003/40001

[commit-bot: I haz the power, 2015-02-05 20:51:36]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-05 20:53:12]

Patchset 3 (id:??) landed as
https://crrev.com/73cb4e12164e4d0023db17b91241b0e77f5d21fd
Cr-Commit-Position: refs/heads/master@{#314870}