Convert printing IPCs to Mojo

components/printing/common/printing.mojom

+// Copyright 2016 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.
+
+module printing.mojom;
+
+import "mojo/common/string16.mojom";
+
+[Native]
+struct PwgRasterSettings;
+
+[Native]
+struct PrinterCapsAndDefaults;
+
+[Native]
+struct PrinterSemanticCapsAndDefaults;
+
+[Native]
+struct LOGFONT;  // Windows-only
+
+[Native]
+struct PdfRenderSettings;
+
+// Called by the utility process to have the browser do font pre-caching.
+interface FontPreCaching {
+  // Windows-only:
+
+  // Request that the given font characters be loaded by the browser so it's
+  // cached by the OS. Please see
+  // PdfToEmfUtilityProcessHostClient::OnPreCacheFontCharacters for details.
+  [Sync]
+  PreCacheFontCharacters(LOGFONT font_data,
+                         mojo.common.mojom.String16 characters) => ();
+};
+
+// These are messages from the browser to the utility process.
+interface Printing {
+  // Tell the utility process to render the given PDF into a PWGRaster. Returns
+  // whether the rendering the PDF to PWG succeeded or not.
+  RenderPDFPagesToPWGRaster(
+      handle input_pdf_file,

[Sam McNally, 2016/12/12 06:09:20]

Use mojo.common.mojom.File for passing files around.

[tibell, 2016/12/13 23:41:55]

Done.

+      PdfRenderSettings settings,
+      PwgRasterSettings bitmap_settings,
+      handle output_pwg_file) => (bool success);
+
+  // Tells the utility process to get capabilities and defaults for the
+  // specified printer. Used on Windows to isolate the service process from
+  // printer driver crashes by executing this in a separate process. This does
+  // not run in a sandbox. If the method fails |caps_and_defaults| will be null.
+  GetPrinterCapsAndDefaults(string printer_name) =>
+      (PrinterCapsAndDefaults? caps_and_defaults);
+
+  // Tells the utility process to get capabilities and defaults for the
+  // specified printer. Used on Windows to isolate the service process from
+  // printer driver crashes by executing this in a separate process. This does
+  // not run in a sandbox. Returns result as
+  // printing::PrinterSemanticCapsAndDefaults. If the method fails
+  // |caps_and_defaults| will be null.
+  GetPrinterSemanticCapsAndDefaults(string printer_name) =>
+      (PrinterSemanticCapsAndDefaults? caps_and_defaults);
+
+  // Windows-only:
+
+  // Tell the utility process to start rendering the given PDF into a
+  // metafile. |page_count| is 0, if loading failed.  Utility process would be
+  // alive until RenderPDFPagesToMetafiles_Stop is called.
+  //
+  // TODO(tibell): Use a null |page_count| for failure.
+  RenderPDFPagesToMetafiles(
+      handle input_file,
+      PdfRenderSettings settings,
+      bool print_text_with_gdi) => (int32 page_count);
+
+  // Requests conversion of the next page.
+  RenderPDFPagesToMetafilesGetPage(int32 page_number, handle output_file) =>
+      (bool success, float scale_factor);
+
+  // Requests utility process to stop conversion and exit.
+  RenderPDFPagesToMetafilesStop();

[Sam McNally, 2016/12/12 06:09:20]

Why not use the closing of the connection to indicate that it should stop?

[tibell, 2016/12/13 23:41:55]

Done.

+};
+
+// Create a printing interface. This is done using a factory so we can pass a
+// |FontPreCaching| callback interface to the receiver side before any of the
+// methods on |Printing| are called.
+interface PrintingFactory {
+  // Creates a new connection using the |printing| pipe.
+  MakePrinting(Printing& printing, FontPreCaching? font_pre_caching);
+};