Make printing work for PDF and Flash.

chrome/browser/printing/print_view_manager.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/browser/printing/print_view_manager.h"
 
 #include <map>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 105 matching lines @@
       rfh->GetRoutingID(), has_selection);
   if (!PrintNowInternal(rfh, std::move(message)))
     return false;
 
   DCHECK(!print_preview_rfh_);
   print_preview_rfh_ = rfh;
   print_preview_state_ = USER_INITIATED_PREVIEW;
   return true;
 }
 
-void PrintViewManager::PrintPreviewForWebNode() {
+void PrintViewManager::PrintPreviewForWebNode(content::RenderFrameHost* rfh) {
   if (print_preview_state_ != NOT_PREVIEWING)
     return;
+
+  DCHECK(rfh);
+  DCHECK(!print_preview_rfh_);
+  print_preview_rfh_ = rfh;

[EhsanK, 2016/11/21 16:39:15]

I was not sure if we are accepting all types of frames here so I had narrowed it
down to only PDF ones. But having it like this I suppose fixes all supported
prints which initiate from the renderer.

I was wondering if there could be cases that we should not support here (no idea
just an uneducated guess).

[Lei Zhang, 2016/11/21 20:07:55]

AFAIK, there's only PDF and Flash. Both of which I have tested with. (I used
--ppapi-flash-path=) I don't know what else can trigger this code.

   print_preview_state_ = USER_INITIATED_PREVIEW;
 }
 
 void PrintViewManager::PrintPreviewDone() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_NE(NOT_PREVIEWING, print_preview_state_);
 
   if (print_preview_state_ == SCRIPTED_PREVIEW) {
     auto& map = g_scripted_print_preview_closure_map.Get();
     auto it = map.find(scripted_print_preview_rph_);
@@ skipping 105 matching lines @@
     IPC_MESSAGE_HANDLER(PrintHostMsg_ShowScriptedPrintPreview,
                         OnShowScriptedPrintPreview)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled ||
          PrintViewManagerBase::OnMessageReceived(message, render_frame_host);
 }
 
 }  // namespace printing