Add public operator== to TransformOperations.

Currently, the equality operator on the following classes are private:
- TranslateTransformOperation
- RotateTransformOperation
- ScaleTransformOperation

So two Translate/Rotate/ScaleTransformOperations cannot be directly
compared. We need to first static_cast them both into TransformOperation
and use the public equality operator on TransformOperation. The equality
operator on TransformOperation is a pure virtual function that just
calls the private equality operators on Translate/Rotate/
ScaleTransformOperations anyway.

To make comparing two Translate/Rotate/ScaleTransformOperations easier,
this patch adds public equality operators to each of those files.
Each of these equality operators only compare with the same type and
simply call the private equality operators.

This allows two Translate/Rotate/ScaleTransformOperations of the same
type to be compared without needing static_cast to a TransformOperation.

Alternatively we could make the private equality operators public, but
I assume there was some reason that they were private. If there's no
particular reason then just making them public is probably better.

This patch also makes a change in StyleTransformData to show that it
works.

Bug: 628043
Change-Id: Ie74931a04f829e5f74348feeca17a75e68046f99
Reviewed-on: https://chromium-review.googlesource.com/527836
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477911}
4 files changed