Print preview page selection should not require a rerendering of draft pages.

chrome/renderer/print_web_view_helper_linux.cc

 // 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.
 
 #include "chrome/renderer/print_web_view_helper.h"
 
 #include "base/file_descriptor_posix.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
@@ skipping 11 matching lines @@
 #include "base/process_util.h"
 #endif  // !defined(OS_CHROMEOS)
 
 using WebKit::WebFrame;
 using WebKit::WebNode;
 
 void PrintWebViewHelper::RenderPreviewPage(int page_number) {
   PrintMsg_PrintPage_Params page_params;
   page_params.params = print_preview_context_.print_params();
   page_params.page_number = page_number;
+  scoped_ptr<printing::Metafile> draft_metafile;
+  printing::Metafile* initial_render_metafile =
+      print_preview_context_.metafile();
+  if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
+    draft_metafile.reset(new printing::PreviewMetafile);
+    initial_render_metafile = draft_metafile.get();
+  }
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   PrintPageInternal(page_params,
                     print_preview_context_.GetPrintCanvasSize(),
-                    print_preview_context_.frame(),
-                    print_preview_context_.metafile());
-
+                    print_preview_context_.frame(), initial_render_metafile);
   print_preview_context_.RenderedPreviewPage(
       base::TimeTicks::Now() - begin_time);
-  scoped_ptr<printing::Metafile> page_metafile;
-  if (print_preview_context_.IsModifiable()) {
-    page_metafile.reset(
+  if (draft_metafile.get()) {
+    draft_metafile->FinishDocument();
+  } else if (print_preview_context_.IsModifiable() &&
+             print_preview_context_.generate_draft_pages()){
+    DCHECK(!draft_metafile.get());
+    draft_metafile.reset(
         print_preview_context_.metafile()->GetMetafileForCurrentPage());
   }
-  PreviewPageRendered(page_number, page_metafile.get());
+  PreviewPageRendered(page_number, draft_metafile.get());
 }
 
 bool PrintWebViewHelper::PrintPages(const PrintMsg_PrintPages_Params& params,
                                     WebFrame* frame,
                                     WebNode* node,
                                     PrepareFrameAndViewForPrint* prepare) {
   printing::NativeMetafile metafile;
   if (!metafile.Init())
     return false;
 
@@ skipping 143 matching lines @@
   SkDevice* device = metafile->StartPageForVectorCanvas(
       page_size, content_area, 1.0f);
   if (!device)
     return;
 
   // The printPage method take a reference to the canvas we pass down, so it
   // can't be a stack object.
   SkRefPtr<skia::VectorCanvas> canvas = new skia::VectorCanvas(device);
   canvas->unref();  // SkRefPtr and new both took a reference.
   printing::MetafileSkiaWrapper::SetMetafileOnCanvas(canvas.get(), metafile);
+  printing::MetafileSkiaWrapper::SetDraftMode(canvas.get(),
+                                              is_print_ready_metafile_sent_);
   frame->printPage(params.page_number, canvas.get());
 
   // TODO(myhuang): We should render the header and the footer.
 
   // Done printing. Close the device context to retrieve the compiled metafile.
   if (!metafile->FinishPage())
     NOTREACHED() << "metafile failed";
 }