Reuse PrintContext to excessively triggering matchMedia('print') listeners.

chrome/renderer/print_web_view_helper.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 #define CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 38 matching lines @@
                               WebKit::WebFrame* frame,
                               const WebKit::WebNode& node);
   ~PrepareFrameAndViewForPrint();
 
   void UpdatePrintParams(const PrintMsg_Print_Params& print_params);
 
   int GetExpectedPageCount() const {
     return expected_pages_count_;
   }
 
-  bool ShouldUseBrowserOverlays() const {
-    return use_browser_overlays_;
-  }
+  bool ShouldUseBrowserOverlays() const;
 
   const gfx::Size& GetPrintCanvasSize() const {
     return print_canvas_size_;
   }
 
   void FinishPrinting();
 
  private:
-  void StartPrinting(const gfx::Size& print_params);
+  void StartPrinting(const gfx::Size& print_params, int dpi);
 
   WebKit::WebFrame* frame_;
-  WebKit::WebNode node_to_print_;
   WebKit::WebView* web_view_;
   gfx::Size print_canvas_size_;
   gfx::Size prev_view_size_;
   gfx::Size prev_scroll_offset_;
   int dpi_;
   int expected_pages_count_;
-  bool use_browser_overlays_;
   bool finished_;
 
   DISALLOW_COPY_AND_ASSIGN(PrepareFrameAndViewForPrint);
 };
 
 // PrintWebViewHelper handles most of the printing grunt work for RenderView.
 // We plan on making print asynchronous and that will require copying the DOM
 // of the document and creating a new WebView with the contents.
 class PrintWebViewHelper
     : public content::RenderViewObserver,
       public content::RenderViewObserverTracker<PrintWebViewHelper>,
       public WebKit::WebViewClient,
       public WebKit::WebFrameClient {
  public:
   explicit PrintWebViewHelper(content::RenderView* render_view);
   virtual ~PrintWebViewHelper();
 
  protected:
   // WebKit::WebViewClient override:
   virtual void didStopLoading();
 
  private:
   friend class PrintWebViewHelperTestBase;
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest,
                            BlockScriptInitiatedPrinting);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, OnPrintPages);
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, PrintWithMediaQuery);
 
 #if defined(OS_WIN) || defined(OS_MACOSX)
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, PrintLayoutTest);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, PrintWithIframe);
 #endif  // defined(OS_WIN) || defined(OS_MACOSX)
 
   // RenderViewObserver implementation.
   virtual bool OnMessageReceived(const IPC::Message& message);
   virtual void PrintPage(WebKit::WebFrame* frame);
 
@@ skipping 312 matching lines @@
 
     State state_;
   };
 
   PrintPreviewContext print_preview_context_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
 #endif  // CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_