Add Print Selection support to Chrome. This change is fairly involved since ...

chrome/renderer/print_web_view_helper.h

 // Copyright (c) 2009 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_DELEGATE_H_
 #define CHROME_RENDERER_PRINT_WEB_VIEW_DELEGATE_H_
 
 #include <vector>
 
 #include "base/scoped_ptr.h"
 #include "webkit/glue/webview_delegate.h"
 
 namespace gfx {
 class Size;
 }
 
 namespace IPC {
 class Message;
 }
 
 class RenderView;
 class WebView;
+struct ViewMsg_Print_Params;
 struct ViewMsg_PrintPage_Params;
 struct ViewMsg_PrintPages_Params;
 
 
 // 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 WebViewDelegate {
  public:
   explicit PrintWebViewHelper(RenderView * render_view)
       : render_view_(render_view) {}
 
   virtual ~PrintWebViewHelper() {}
 
   void SyncPrint(WebFrame* frame);
 
+  // Is there a background print in progress?
+  bool IsPrinting() {
+    return print_web_view_.get() != NULL;
+  }
+
+  // Notification when printing is done - signal teardown
+  void DidFinishPrinting(bool success);
+
  protected:
+  bool CopyAndPrint(const ViewMsg_PrintPages_Params& params,
+                    WebFrame* web_frame);
 
   // Prints the page listed in |params|.
   void PrintPage(const ViewMsg_PrintPage_Params& params,
                  const gfx::Size& canvas_size,
                  WebFrame* frame);
 
   // Prints all the pages listed in |params|.
+  // It will implicitly revert the document to display CSS media type.
   void PrintPages(const ViewMsg_PrintPages_Params& params, WebFrame* frame);
 
   // IPC::Message::Sender
   bool Send(IPC::Message* msg);
 
   int32 routing_id();
 
   // WebViewDeletegate
-  virtual void DidStartLoading(WebView* webview) {}
   virtual void DidStopLoading(WebView* webview);
   virtual gfx::NativeViewId GetContainingView(WebWidget* webwidget);
   virtual void DidInvalidateRect(WebWidget* webwidget,
                                  const WebKit::WebRect& rect) {}
   virtual void DidScrollRect(WebWidget* webwidget, int dx, int dy,
                              const WebKit::WebRect& clip_rect) {}
   virtual void Show(WebWidget* webwidget, WindowOpenDisposition disposition) {}
   virtual void ShowAsPopupWithItems(WebWidget* webwidget,
                                     const WebKit::WebRect& bounds,
                                     int item_height,
@@ skipping 12 matching lines @@
   virtual void DidMove(WebWidget* webwidget, const WebPluginGeometry& move) {}
   virtual void RunModal(WebWidget* webwidget) {}
   virtual void AddRef() {}
   virtual void Release() {}
   virtual bool IsHidden(WebWidget* webwidget);
   virtual WebKit::WebScreenInfo GetScreenInfo(WebWidget* webwidget);
 
  private:
   RenderView* render_view_;
   scoped_ptr<WebView> print_web_view_;
+  scoped_ptr<ViewMsg_PrintPages_Params> print_pages_params_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
 #endif  // CHROME_RENDERER_PRINT_WEB_VIEW_DELEGATE_H_