refactor: printing implementation (#15143)

* refactor: basic printing

* move build files to chromium_src/BUILD.gn
* remove dependency on chrome prerender sources

* spec: move printing specs behind feature flag

* build: register pdf compositor service

atom/renderer/printing/print_render_frame_helper_delegate.cc

@@ -0,0 +1,37 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/renderer/printing/print_render_frame_helper_delegate.h"
+
+#include "content/public/renderer/render_frame.h"
+#include "third_party/blink/public/web/web_element.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+
+namespace atom {
+
+PrintRenderFrameHelperDelegate::PrintRenderFrameHelperDelegate() = default;
+
+PrintRenderFrameHelperDelegate::~PrintRenderFrameHelperDelegate() = default;
+
+bool PrintRenderFrameHelperDelegate::CancelPrerender(
+    content::RenderFrame* render_frame) {
+  return false;
+}
+
+// Return the PDF object element if |frame| is the out of process PDF extension.
+blink::WebElement PrintRenderFrameHelperDelegate::GetPdfElement(
+    blink::WebLocalFrame* frame) {
+  return blink::WebElement();
+}
+
+bool PrintRenderFrameHelperDelegate::IsPrintPreviewEnabled() {
+  return false;
+}
+
+bool PrintRenderFrameHelperDelegate::OverridePrint(
+    blink::WebLocalFrame* frame) {
+  return false;
+}
+
+}  // namespace atom