Revert "remove legacy forward declares"

This reverts commit 00dcf668659ab26b8691c64a977fdd19e9e8df09.

Reason for revert: breaks IWYU on chrome/win and google3

Original change's description:
> remove legacy forward declares
> 
> Bug: skia:
> Change-Id: Ie83cef8e47b27c3a59fe251b9c81dca7c4d15232
> Reviewed-on: https://skia-review.googlesource.com/c/188820
> Reviewed-by: Mike Reed <reed@google.com>
> Auto-Submit: Mike Reed <reed@google.com>
> Commit-Queue: Ravi Mistry <rmistry@google.com>

TBR=rmistry@google.com,reed@google.com

Change-Id: I2931fb7d24c8a908be4a21a52e4ef0caf6618f32
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/c/188821
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed