Revert 273079 "Add content renderer to the GN build"

trunk/src/content/public/renderer/BUILD.gn

-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import("//build/config/features.gni")
-import("//content/renderer/renderer.gni")
-
-source_set("renderer") {
-  sources = rebase_path(content_renderer_gypi_values.public_renderer_sources,
-                        ".", "//content")
-
-  configs += [
-    "//content:blink_headers_stub_config",
-    "//content:content_implementation",
-    "//content:libjingle_stub_config",
-    "//content:v8_stub_config",
-    "//content:widevine_stub_config",
-  ]
-
-  deps = [
-    "//content/renderer",
-    "//skia",
-  ]
-
-  if (enable_webrtc) {
-    sources += rebase_path(
-        content_renderer_gypi_values.public_renderer_webrtc_sources,
-        ".", "//content")
-  }
-}