Add rotateRadians function to AffineTransform

Currently, rotate function takes an argument in only degrees.
In many cases, rotate function is often required radian value instead of degree value.
If we add new rotateRadians function, we will be able to reduce unnecessary operations.

 Before : rad -> rad2deg -> deg2rad -> calc sinNcos
 After  : rad                       -> calc sinNcos

As a result, we can reduce two multiplication and two division.

Similar case: https://bugs.webkit.org/show_bug.cgi?id=87317
Applications: https://codereview.chromium.org/173593002/

Review URL: https://codereview.chromium.org/166273019

git-svn-id: svn://svn.chromium.org/blink/trunk@167603 bbb929c8-8fbe-4397-9dbb-9b2b20218538