Revert of Implement Aura side of unified touch text selection for contents

ui/touch_selection/BUILD.gn

Index: ui/touch_selection/BUILD.gn
diff --git a/ui/touch_selection/BUILD.gn b/ui/touch_selection/BUILD.gn
index f5f2825f2eb7a07432e8c5dda0704b6586eebd01..3f98ea08cebf6716df2f11c0b5a83fc510d07f6f 100644
--- a/ui/touch_selection/BUILD.gn
+++ b/ui/touch_selection/BUILD.gn
@@ -53,19 +53,6 @@
   }
 }
 
-static_library("test_support") {
-  testonly = true
-
-  sources = [
-    "touch_selection_controller_test_api.cc",
-    "touch_selection_controller_test_api.h",
-  ]
-
-  deps = [
-    ":touch_selection",
-  ]
-}
-
 # TODO(GYP): Delete this after we've converted everything to GN.
 # The _run targets exist only for compatibility w/ GYP.
 group("ui_touch_selection_unittests_run") {
@@ -83,7 +70,6 @@
   ]
 
   deps = [
-    ":test_support",
     ":touch_selection",
     "//base/test:run_all_unittests",
     "//testing/gmock:gmock",