Defer request to print a PDF when the user initiates the entire frame and the PDF hasn't loaded.

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 802 matching lines @@
     return !IsScriptInitiatedPrintTooFrequent(frame);
   return true;
 }
 
 void PrintWebViewHelper::DidStartLoading() {
   is_loading_ = true;
 }
 
 void PrintWebViewHelper::DidStopLoading() {
   is_loading_ = false;
-  ShowScriptedPrintPreview();
+  if (!on_stop_loading_closure_.is_null())

[Vitaly Buka (NO REVIEWS), 2014/08/14 05:19:43]

on_stop_loading_closure_.reset() after run

[ivandavid, 2014/08/15 00:35:23]

Done.

+    on_stop_loading_closure_.Run();
 }
 
 // Prints |frame| which called window.print().
 void PrintWebViewHelper::PrintPage(blink::WebLocalFrame* frame,
                                    bool user_initiated) {
   DCHECK(frame);
 
   // Allow Prerendering to cancel this print request if necessary.
   if (prerender::PrerenderHelper::IsPrerendering(
           render_view()->GetMainRenderFrame())) {
@@ skipping 858 matching lines @@
             print_preview_context_.IsModifiable()));
   }
 }
 
 void PrintWebViewHelper::RequestPrintPreview(PrintPreviewRequestType type) {
   const bool is_modifiable = print_preview_context_.IsModifiable();
   const bool has_selection = print_preview_context_.HasSelection();
   PrintHostMsg_RequestPrintPreview_Params params;
   params.is_modifiable = is_modifiable;
   params.has_selection = has_selection;
+  DCHECK(!GetPlugin(print_preview_context_.source_frame()));

[Vitaly Buka (NO REVIEWS), 2014/08/14 05:19:43]

this DCHECK makes no sense
if it was correct, all your changes irrelevant.

only PRINT_PREVIEW_USER_INITIATED_SELECTION needs this DCHECK

[ivandavid, 2014/08/15 00:35:23]

Done.

   switch (type) {
     case PRINT_PREVIEW_SCRIPTED: {
       // Shows scripted print preview in two stages.
       // 1. PrintHostMsg_SetupScriptedPrintPreview blocks this call and JS by
       //    pumping messages here.
       // 2. PrintHostMsg_ShowScriptedPrintPreview shows preview once the
       //    document has been loaded.
       is_scripted_preview_delayed_ = true;
       if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
         // Wait for DidStopLoading. Plugins may not know the correct
         // |is_modifiable| value until they are fully loaded, which occurs when
         // DidStopLoading() is called. Defer showing the preview until then.
+        on_stop_loading_closure_ =
+            base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
+                       base::Unretained(this));
       } else {
         base::MessageLoop::current()->PostTask(
             FROM_HERE,
             base::Bind(&PrintWebViewHelper::ShowScriptedPrintPreview,
                        weak_ptr_factory_.GetWeakPtr()));
       }
       IPC::SyncMessage* msg =
           new PrintHostMsg_SetupScriptedPrintPreview(routing_id());
       msg->EnableMessagePumping();
       Send(msg);
       is_scripted_preview_delayed_ = false;
       return;
     }
     case PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME: {
+      // Wait for DidStopLoading. Continuing with this function while
+      // |is_loading_| is true will cause print preview to hang when try to
+      // print a PDF document.
+      if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
+        on_stop_loading_closure_ =
+            base::Bind(&PrintWebViewHelper::RequestPrintPreview,
+                       base::Unretained(this),
+                       type);
+        return;
+      }
+
       break;
     }
     case PRINT_PREVIEW_USER_INITIATED_SELECTION: {
       DCHECK(has_selection);
       params.selection_only = has_selection;
       break;
     }
     case PRINT_PREVIEW_USER_INITIATED_CONTEXT_NODE: {
+      // Same situation as in PRINT_PREVIEW_USER_INITIATED_ENTIRE_FRAME.
+      if (is_loading_ && GetPlugin(print_preview_context_.source_frame())) {
+        on_stop_loading_closure_ =
+            base::Bind(&PrintWebViewHelper::RequestPrintPreview,
+                       base::Unretained(this),
+                       type);
+        return;
+      }
+
       params.webnode_only = true;
       break;
     }
     default: {
       NOTREACHED();
       return;
     }
   }
   Send(new PrintHostMsg_RequestPrintPreview(routing_id(), params));
 }
@@ skipping 285 matching lines @@
 }
 
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
   pages_to_render_.clear();
   error_ = PREVIEW_ERROR_NONE;
 }
 
 }  // namespace printing