Remove one SVG animated type special case from the bindings generator

Remove one SVG animated type special case from the bindings generator that
would append 'Animated' to the implementation getter method.
Instead, the implementation methods are renamed to match the IDL attribute
name.

To avoid naming clashes, existing getters were renamed *CurrentValue() since they
return the current value of the animated property. This naming is consistent
with the existing *BaseValue() methods.

IsSVGAnimatedType() subroutine is not removed from the generator yet as it
is still needed. It will be removed in a later commit.

Review URL: https://chromiumcodereview.appspot.com/19097005

git-svn-id: svn://svn.chromium.org/blink/trunk@154121 bbb929c8-8fbe-4397-9dbb-9b2b20218538