App install alerts: String and fling tweaks
* Resets gestures when a fling is detected to get the proper gesture direction. This prevents oddball cases where the user starts scrolling in one direction and flings in the other at the top of the page.
* Applies a character limit to the "Installing..." and "Open" strings because tiny buttons can't support these long strings.
BUG=359196,363832
Review URL: https://codereview.chromium.org/
247693002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265361 0039d316-1c4b-4281-b951-d872f2087c98