Fix print preview draft page memory leaks.

chrome/renderer/print_web_view_helper_win.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/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
@@ skipping 122 matching lines @@
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   RenderPage(print_params, &scale_factor, page_number, true,
              print_preview_context_.frame(), &metafile);
 
   print_preview_context_.RenderedPreviewPage(
       base::TimeTicks::Now() - begin_time);
 
   // Release since |print_preview_context_| is the real owner.
   metafile.release();
-  printing::Metafile* page_metafile = NULL;
+  scoped_ptr<printing::Metafile> page_metafile;
   if (print_preview_context_.IsModifiable()) {
-    page_metafile = reinterpret_cast<printing::PreviewMetafile*>(
-        print_preview_context_.metafile())->GetMetafileForCurrentPage();
+    page_metafile.reset(reinterpret_cast<printing::PreviewMetafile*>(
+        print_preview_context_.metafile())->GetMetafileForCurrentPage());
   }
-  PreviewPageRendered(page_number, page_metafile);
+  PreviewPageRendered(page_number, page_metafile.get());
 }
 
 void PrintWebViewHelper::RenderPage(
     const PrintMsg_Print_Params& params, float* scale_factor, int page_number,
     bool is_preview, WebFrame* frame, scoped_ptr<Metafile>* metafile) {
   PageSizeMargins page_layout_in_points;
   GetPageSizeAndMarginsInPoints(frame, page_number, params,
                                 &page_layout_in_points);
 
   int width;
@@ skipping 122 matching lines @@
     shared_buf.Unmap();
     return false;
   }
   shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), shared_mem_handle);
   shared_buf.Unmap();
 
   Send(new PrintHostMsg_DuplicateSection(routing_id(), *shared_mem_handle,
                                          shared_mem_handle));
   return true;
 }