Removes individual instances of Details structure in WindowResizer subclasses and adds DragDetails to WindowState. It is possible to access the current WindowResizer during the drag via window_state->drag_details()->window_resizer.
Simplifies construction of WindowResizer chain by creating DragDetails once at a point where creation of the resizer chain is imminent (after all checks that would return empty WindowResizer object are made).

Keeps track of whether currently dragged window is a panel attached to the shelf and if so prevents it from indicating that it can be docked (and from getting docked).

BUG=310931

Review URL: https://codereview.chromium.org/121153003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244246 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244246