Use WebLocalFrame::isLoading(), not WebFrame::isLoading(), in print preview.

android_webview/renderer/print_web_view_helper.cc

 // Copyright 2013 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.
 
 // TODO(sgurun) copied from chrome/renderer. Remove after crbug.com/322276
 
 #include "android_webview/renderer/print_web_view_helper.h"
 
 #include <string>
 
@@ skipping 706 matching lines @@
 void PrepareFrameAndViewForPrint::RestoreSize() {
   if (frame()) {
     blink::WebView* web_view = frame_.GetFrame()->view();
     web_view->resize(prev_view_size_);
     if (blink::WebFrame* web_frame = web_view->mainFrame())
       web_frame->setScrollOffset(prev_scroll_offset_);
   }
 }
 
 void PrepareFrameAndViewForPrint::FinishPrinting() {
-  blink::WebFrame* frame = frame_.GetFrame();
+  blink::WebLocalFrame* frame = frame_.GetFrame();
   if (frame) {
     blink::WebView* web_view = frame->view();
     if (is_printing_started_) {
       is_printing_started_ = false;
       frame->printEnd();
       if (!owns_web_view_) {
         web_view->settings()->setShouldPrintBackgrounds(false);
         RestoreSize();
       }
     }
@@ skipping 1278 matching lines @@
 }
 
 void PrintWebViewHelper::PrintPreviewContext::ClearContext() {
   prep_frame_view_.reset();
   metafile_.reset();
   pages_to_render_.clear();
   error_ = PREVIEW_ERROR_NONE;
 }
 
 }  // namespace printing