Revert "Add Atlas Text interface for rendering SDF glyphs."

This reverts commit 39631f3df172feb385527a5d125bc53b0bded7e6.

Reason for revert: break google3 rool

Original change's description:
> Add Atlas Text interface for rendering SDF glyphs.
> 
> This new API is built upon SDF text atlas code from the GPU backend. Unlike using the GPU
> backend to draw text, this set of interfaces allows the client to render the SDF glyphs. The
> client issues text draws to potentially multiple targets and then the client flushes. The
> client then gets commands from Skia with data to put into a texture atlas and vertices to
> draw that reference the texture. The client is responsible for creating the texture, uploading
> the SDF data to the texture, and drawing the vertices provided by Skia.
> 
> Change-Id: Ie9447e19b85f0ce1c2b942e5216c787a74f335d3
> Reviewed-on: https://skia-review.googlesource.com/59360
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=jvanverth@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: I4aad0c99e645b476fd8ba25731f2a10e8802bb25
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/73420
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/gn/gm.gni b/gn/gm.gni
index 22d562f187..441c041e6f 100644
--- a/gn/gm.gni
+++ b/gn/gm.gni
@@ -22,7 +22,6 @@ gm_sources = [
   "$_gm/arcofzorro.cpp",
   "$_gm/arcto.cpp",
   "$_gm/arithmode.cpp",
-  "$_gm/atlastext.cpp",
   "$_gm/badpaint.cpp",
   "$_gm/beziereffects.cpp",
   "$_gm/beziers.cpp",