Make printing work for PDF and Flash.

chrome/browser/printing/print_view_manager.cc

Index: chrome/browser/printing/print_view_manager.cc
diff --git a/chrome/browser/printing/print_view_manager.cc b/chrome/browser/printing/print_view_manager.cc
index 6afd07b443725b2bb3b55f195554bbb458a5b643..ea49f9b888e4f33ba9966739c1c0e1585eada2b8 100644
--- a/chrome/browser/printing/print_view_manager.cc
+++ b/chrome/browser/printing/print_view_manager.cc
@@ -123,9 +123,13 @@ bool PrintViewManager::PrintPreviewNow(content::RenderFrameHost* rfh,
   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;
 }