Add a way for notifications to be linked from settings dialog.

Adds an event, onShowSettings, that is fired when the link is clicked.
The link is only shown when the event is subscribed to.

BUG=304208,286608

Review URL: https://codereview.chromium.org/26876006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232439 0039d316-1c4b-4281-b951-d872f2087c98
Pepper: Move FileIO host from renderer to browser.

This change is large because it moves QuotaFileIO and PepperFileIOHost all at
once to the browser process. Some code in the refactored PepperFileIOHost is
moved from what's provided in FileAPIMessageFilter.

Tested locally with Bastion, From Dust, and Angry Bots.

TBR=jschuh
BUG=246396

Review URL: https://codereview.chromium.org/33053002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232440 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232440