Remove SkAtlasTextTarget

I can find no references to SkAtlasTextTarget in AOSP or in Chromium.
With google3 CL/314226466 there are no more uses in Google3.

Change-Id: I60b5f06fc17c0e4f8d008886c96645475e3d48e5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/293839
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index b0d9425..7a6994c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -41,9 +41,6 @@
   if (!skia_enable_gpu) {
     defines += [ "SK_SUPPORT_GPU=0" ]
   }
-  if (skia_enable_atlas_text) {
-    defines += [ "SK_SUPPORT_ATLAS_TEXT=1" ]
-  }
   if (is_fuchsia) {
     defines += fuchsia_defines
   }
@@ -639,10 +636,6 @@
     cflags_objcc += [ "-fobjc-arc" ]
   }
 
-  if (skia_enable_atlas_text) {
-    sources += skia_atlas_text_sources
-  }
-
   if (is_debug) {
     public_defines += [ "SK_ENABLE_DUMP_GPU" ]
   }
@@ -1157,7 +1150,6 @@
   skia_public_includes = [
     "client_utils/android",
     "include/android",
-    "include/atlastext",
     "include/c",
     "include/codec",
     "include/config",
@@ -1353,10 +1345,8 @@
     libs = []
 
     if (skia_use_gl) {
-      sources += [
-        "tools/gpu/atlastext/GLTestAtlasTextRenderer.cpp",
-        "tools/gpu/gl/command_buffer/GLTestContext_command_buffer.cpp",
-      ]
+      sources +=
+          [ "tools/gpu/gl/command_buffer/GLTestContext_command_buffer.cpp" ]
       if (is_ios) {
         sources += [ "tools/gpu/gl/iOS/CreatePlatformGLTestContext_iOS.mm" ]
         libs += [ "OpenGLES.framework" ]