Handle an extension printer supporting only PWG raster data

chrome/browser/ui/webui/print_preview/printer_handler.h

 // Copyright 2015 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINTER_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINTER_HANDLER_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 class RefCountedMemory;
 }
 
 namespace content {
 class BrowserContext;
 }
 
+namespace gfx {
+class Size;
+}
+
 // Wrapper around PrinterProviderAPI to be used by print preview.
 // It makes request lifetime management easier, and hides details of more
 // complex operations like printing from the print preview handler.
 // TODO(tbarzic): Use the same interface for other printer types.
 class PrinterHandler {
  public:
   using GetPrintersCallback =
       base::Callback<void(const base::ListValue& printers, bool done)>;
   using GetCapabilityCallback =
       base::Callback<void(const std::string& printer_id,
@@ skipping 23 matching lines @@
   // Starts a print request.
   // |destination_id|: The printer to which print job should be sent.
   // |capability|: Capability reported by the printer.
   // |ticket_json|: The print job ticket as JSON string.
   // |print_data|: The document bytes to print.
   // |callback| should be called in the response to the request.
   virtual void StartPrint(
       const std::string& destination_id,
       const std::string& capability,
       const std::string& ticket_json,
+      const gfx::Size& size,

[Vitaly Buka (NO REVIEWS), 2015/02/17 19:43:54]

size is a property of document, ideally we need to get it from there.
it's even invalid with multi-sized pdfs. Can you drop some TODO about that?

maybe TODO(): get source size from print_data.

[tbarzic, 2015/02/18 02:55:49]

So, basically, the page size should be extracted from document data when
processing a page in PDFiumEngineExports::RenderPDFPageToBitmap (and then used
to calculate the bitmap size), right?

Added TODO, and also renamed it to |page_size|, to be less vague.

       const scoped_refptr<base::RefCountedMemory>& print_data,
       const PrintCallback& callback) = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_PRINTER_HANDLER_H_