[sql] Complain about statement mutations after stepping has started.

DCHECK if any Bind*() calls occur after Step() has been called.  The
bind cannot be implemented at that point, so most likely the calling
code has an error, such as a forgotted Reset().

Also DCHECK if Run() is called after Run() or Step() without an
intervening Reset().  Such a calling sequence is unlikely to be
intentional, because the results of calling Run() twice aren't
defined.

BUG=309759

Review URL: https://codereview.chromium.org/40733003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231098 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231098
Update comments for MediaStreamRequest::requesting_*_id and MediaStreamRequest::render_*_id to make the distinction more clear.

BUG=311027
NOTRY=true

Review URL: https://codereview.chromium.org/40553003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231100 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231100