undef SK_SUPPORT_LEGACY_ONLOCKPIXELS since all subclass now support the new virtual onNewLockPixels

BUG=

Review URL: https://codereview.chromium.org/132803011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249867 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249867