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/browser/printing/print_preview_message_handler.h

@@ -0,0 +1,74 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_
+#define ATOM_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_
+
+#include <map>
+
+#include "base/memory/ref_counted_memory.h"
+#include "base/memory/weak_ptr.h"
+#include "components/services/pdf_compositor/public/interfaces/pdf_compositor.mojom.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+#include "v8/include/v8.h"
+
+struct PrintHostMsg_DidPreviewDocument_Params;
+struct PrintHostMsg_PreviewIds;
+
+namespace content {
+class RenderFrameHost;
+}
+
+namespace atom {
+
+// Manages the print preview handling for a WebContents.
+class PrintPreviewMessageHandler
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<PrintPreviewMessageHandler> {
+ public:
+  using PrintToPDFCallback =
+      base::Callback<void(v8::Local<v8::Value>, v8::Local<v8::Value>)>;
+
+  ~PrintPreviewMessageHandler() override;
+
+  void PrintToPDF(const base::DictionaryValue& options,
+                  const PrintToPDFCallback& callback);
+
+ protected:
+  // content::WebContentsObserver implementation.
+  bool OnMessageReceived(const IPC::Message& message,
+                         content::RenderFrameHost* render_frame_host) override;
+
+ private:
+  friend class content::WebContentsUserData<PrintPreviewMessageHandler>;
+
+  explicit PrintPreviewMessageHandler(content::WebContents* web_contents);
+
+  void OnMetafileReadyForPrinting(
+      content::RenderFrameHost* render_frame_host,
+      const PrintHostMsg_DidPreviewDocument_Params& params,
+      const PrintHostMsg_PreviewIds& ids);
+  void OnCompositePdfDocumentDone(int page_number,
+                                  const PrintHostMsg_PreviewIds& ids,
+                                  printing::mojom::PdfCompositor::Status status,
+                                  base::ReadOnlySharedMemoryRegion region);
+  void OnPrintPreviewFailed(int document_cookie,
+                            const PrintHostMsg_PreviewIds& ids);
+  void OnPrintPreviewCancelled(int document_cookie,
+                               const PrintHostMsg_PreviewIds& ids);
+  void RunPrintToPDFCallback(int request_id,
+                             scoped_refptr<base::RefCountedMemory> data_bytes);
+
+  using PrintToPDFCallbackMap = std::map<int, PrintToPDFCallback>;
+  PrintToPDFCallbackMap print_to_pdf_callback_map_;
+
+  base::WeakPtrFactory<PrintPreviewMessageHandler> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintPreviewMessageHandler);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_