Add brightness/grayscale animations and use them for OOBE boot transition.
Add support for both boot up/boot down animations.
Checked, looks fine on x86-alex, stumpy.
BUG=133279
TEST=LayerAnimatorTest.[GetTargetBrightness|GetTargetGrayscale], LayerAnimationElementTest.[BrightnessElement|GrayscaleElement], WindowAnimationsTest.HideShowBrightnessGrayscaleAnimation
Review URL: https://chromiumcodereview.appspot.com/10800020
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@147786 0039d316-1c4b-4281-b951-d872f2087c98
18 files changed
