Move components/nacl/{common -> browser}/nacl_browser_delegate.h

This delegate interface is used only for browser specifc code, and
further modification for 298339 needs to add references to
content/public/browser.

BUG=298339

Review URL: https://codereview.chromium.org/73123005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235900 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235900