[Chrome] Support NumCopies print preset

chrome/renderer/printing/print_web_view_helper.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/renderer/printing/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
@@ skipping 994 matching lines @@
       notify_browser_of_print_failure_ = false;  // Already sent.
     }
     DidFinishPrinting(FAIL_PREVIEW);
     return;
   }
 
   // Set the options from document if we are previewing a pdf and send a
   // message to browser.
   if (print_pages_params_->params.is_first_request &&
       !print_preview_context_.IsModifiable()) {
     PrintHostMsg_SetOptionsFromDocument_Params params;

[Vitaly Buka (NO REVIEWS), 2014/09/03 21:36:24]

Why this one is not enough? becase of out-of-process?
So scaling also didn't work before?

[Nikhil, 2014/09/04 11:42:53]

This one is enough when we use PPP interfaces i.e. browser to plugin. During
PrintWebViewHelper::OnPrintPreview(), we request options from plugin and set
them by sending message to browser. So scaling works since it uses PPP
interface. I used this approach in initial patch for NumCopies.

But now that we have moved to PPB interface i.e. plugin to browser for this
patch, using same IPC again doesn't seem to work. Current patch uses following
approach -

[1] Set options from document in Instance::DocumentLoadComplete() 
(https://codereview.chromium.org/375253002/diff/100001/pdf/instance.cc)

[2] Send these options through PPB interface to
PepperPrintingRendererHost::OnHostMsgSetPrintPresetOptionsFromDocument (added in
this patch).

[3] Inform PrintPreviewUI to update settings.
(https://codereview.chromium.org/375253002/diff2/80001:100001/chrome/renderer/...)

The step [3] is giving problem. When I send PrintHostMsg_SetOptionsFromDocument
IPC message, nothing happens. I've tried sending this IPC from helper and from
PepperPrintingRendererHost to no avail.

I'm suspecting the interaction model might be incorrect.

FWIW, I can send ChromeViewHostMsg just fine. I tried sending ChromeViewHostMsg
to chrome/browser/renderer_host/ from PepperPrintingRendererHost. That is
browser thread I think, but I was unable to get WebContents required to get
PrintPreviewUI.

Hope the above makes some sense. Please let me know WDYT.

Also, please see (maybe relevant?) - 
https://code.google.com/p/chromium/codesearch#chromium/src/ppapi/proxy/flash_...

[Vitaly Buka (NO REVIEWS), 2014/09/08 18:52:26]

Discussed in chat.

On 2014/09/04 11:42:53, Nikhil wrote:

     SetOptionsFromDocument(params);
     Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), params));
   }
 
   is_print_ready_metafile_sent_ = false;
 
   // PDF printer device supports alpha blending.
   print_pages_params_->params.supports_alpha_blend = true;
 
   bool generate_draft_pages = false;
@@ skipping 193 matching lines @@
   print_node_in_progress_ = true;
 
   // Make a copy of the node, in case RenderView::OnContextMenuClosed resets
   // its |context_menu_node_|.
   print_preview_context_.InitWithNode(node);
   RequestPrintPreview(PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE);
 
   print_node_in_progress_ = false;
 }
 
+void PrintWebViewHelper::SetPrintPresetOptionsFromDocument(
+    PrintHostMsg_SetOptionsFromDocument_Params& params) {
+  // FIXME: Send message to browser to set print preset options.
+  Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), params));
+}
+
 #if !defined(OS_WIN)
 void PrintWebViewHelper::Print(blink::WebLocalFrame* frame,
                                const blink::WebNode& node) {
   // If still not finished with earlier print request simply ignore.
   if (prep_frame_view_)
     return;
 
   FrameReference frame_ref(frame);
 
   int expected_page_count = 0;
@@ skipping 725 matching lines @@
 }
 
 void PrintWebViewHelper::SetPrintPagesParams(
     const PrintMsg_PrintPages_Params& settings) {
   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
                                              settings.params.document_cookie));
 }
 
 }  // namespace printing