some fixes and warning disables in ui/ for building on win x64

- Some |int|s that should be |ptrdiff_t|s.
- Icon structures are packing to known size (same signs).
- GetWindowLong needs to be GetWindowLongPtr to work on 32 & 64.

R=ben@chromium.org, jschuh@chromium.org
BUG=167187, 166496

Review URL: https://chromiumcodereview.appspot.com/11889017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@176860 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed