Revert of scheduler: Always create a real scheduler in unit tests

components/scheduler/BUILD.gn

Index: components/scheduler/BUILD.gn
diff --git a/components/scheduler/BUILD.gn b/components/scheduler/BUILD.gn
index 587516f3ecb5ee4525f627a2bb0e538593fac3db..f55b542fe95c14f14222b5dd450e6e02baf30740 100644
--- a/components/scheduler/BUILD.gn
+++ b/components/scheduler/BUILD.gn
@@ -60,14 +60,3 @@
     "//testing/gtest",
   ]
 }
-
-# GYP version: components/scheduler.gypi:scheduler_test_support
-static_library("test_support") {
-  sources = rebase_path(scheduler_gypi_values.scheduler_test_support_sources,
-                        ".",
-                        "//components/scheduler")
-
-  deps = [
-    "//base",
-  ]
-}