Clean up constructors

And, use C++ style casts and use float math functions rather than double ones to save memory space.

Also, stop using FloatMath and NativeUtils as standard Math methods are faster now.
See http://code.google.com/p/android/issues/detail?id=36199 and https://android-review.googlesource.com/40700

multi-project commit with I4259fb5ab8a15ac5760a7f04fc8f4c860529f04a

Change-Id: I0b81cff8c91769f7559a59b9528c75a5aabb4211