Fix memory leak of PreviewModeClient in PDF

pdf/out_of_process_instance.h

 // Copyright (c) 2012 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 PDF_OUT_OF_PROCESS_INSTANCE_H_
 #define PDF_OUT_OF_PROCESS_INSTANCE_H_
 
 #include <queue>
 #include <set>
 #include <string>
@@ skipping 243 matching lines @@
   };
 
   PrintSettings print_settings_;
 
   scoped_ptr<PDFEngine> engine_;
 
   // This engine is used to render the individual preview page data. This is
   // used only in print preview mode. This will use |PreviewModeClient|
   // interface which has very limited access to the pp::Instance.
   scoped_ptr<PDFEngine> preview_engine_;
+  scoped_ptr<PreviewModeClient> preview_client_;

[Lei Zhang, 2015/09/07 19:31:46]

Doesn't member destruction go bottom up? i.e. as is, |preview_client_| will be
freed before |preview_engine_|, though |preview_engine_| still has a pointer to
|preview_client_|.

[raymes, 2015/09/07 23:59:00]

Done.

 
   std::string url_;
 
   // Used for submitting forms.
   pp::CompletionCallbackFactory<OutOfProcessInstance> form_factory_;
   pp::URLLoader form_loader_;
 
   // Used for printing without re-entrancy issues.
   pp::CompletionCallbackFactory<OutOfProcessInstance> print_callback_factory_;
 
@@ skipping 62 matching lines @@
   // The blank space above the first page of the document reserved for the
   // toolbar.
   int top_toolbar_height_;
 
   DISALLOW_COPY_AND_ASSIGN(OutOfProcessInstance);
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_OUT_OF_PROCESS_INSTANCE_H_