Fix for frame buffer resizing when new size is less than 8 bytes larger than old size. Changed several ints to size_t.

      BUG=55119
TEST=None

Review URL: http://codereview.chromium.org/3302024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@59384 0039d316-1c4b-4281-b951-d872f2087c98