Fire visibilityChange event on out-of-process iframes.

components/printing/renderer/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 "components/printing/renderer/print_web_view_helper.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <string>
 #include <utility>
@@ skipping 504 matching lines @@
     const PageSizeMargins& page_layout,
     const PrintMsg_Print_Params& params) {
   SkAutoCanvasRestore auto_restore(canvas, true);
   canvas->scale(1 / webkit_scale_factor, 1 / webkit_scale_factor);
 
   blink::WebSize page_size(page_layout.margin_left + page_layout.margin_right +
                                page_layout.content_width,
                            page_layout.margin_top + page_layout.margin_bottom +
                                page_layout.content_height);
 
-  blink::WebView* web_view = blink::WebView::create(NULL);
+  blink::WebView* web_view =
+      blink::WebView::create(nullptr, blink::WebPageVisibilityStateVisible);
   web_view->settings()->setJavaScriptEnabled(true);
 
   blink::WebLocalFrame* frame =
       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, NULL);
   web_view->setMainFrame(frame);
 
   base::StringValue html(ResourceBundle::GetSharedInstance().GetLocalizedString(
       IDR_PRINT_PREVIEW_PAGE));
   // Load page with script to avoid async operations.
   ExecuteScript(frame, kPageLoadScriptFormat, html);
@@ skipping 196 matching lines @@
   std::string url_str = "data:text/html;charset=utf-8,";
   url_str.append(
       net::EscapeQueryParamValue(frame()->selectionAsMarkup().utf8(), false));
   RestoreSize();
   // Create a new WebView with the same settings as the current display one.
   // Except that we disable javascript (don't want any active content running
   // on the page).
   WebPreferences prefs = preferences;
   prefs.javascript_enabled = false;
 
-  blink::WebView* web_view = blink::WebView::create(this);
+  blink::WebView* web_view =
+      blink::WebView::create(this, blink::WebPageVisibilityStateVisible);
   owns_web_view_ = true;
   content::RenderView::ApplyWebPreferences(prefs, web_view);
   web_view->setMainFrame(
       blink::WebLocalFrame::create(blink::WebTreeScopeType::Document, this));
   frame_.Reset(web_view->mainFrame()->toWebLocalFrame());
   node_to_print_.reset();
 
   // When loading is done this will call didStopLoading() and that will do the
   // actual printing.
   frame()->loadRequest(blink::WebURLRequest(GURL(url_str)));
@@ skipping 1497 matching lines @@
       blink::WebConsoleMessage::LevelWarning, message));
   return false;
 }
 
 void PrintWebViewHelper::ScriptingThrottler::Reset() {
   // Reset counter on successful print.
   count_ = 0;
 }
 
 }  // namespace printing