Fix Pepper file chooser

webkit/plugins/ppapi/ppb_file_chooser_impl.cc

 // 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.
 
 #include "webkit/plugins/ppapi/ppb_file_chooser_impl.h"
 
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 39 matching lines @@
   }
 
   virtual ~FileChooserCompletionImpl() {}
 
   virtual void didChooseFile(const WebVector<WebString>& file_names) {
     std::vector<std::string> files;
     for (size_t i = 0; i < file_names.size(); i++)
       files.push_back(file_names[i].utf8());
 
     file_chooser_->StoreChosenFiles(files);
+
+    // It is the responsibility of this method to delete the instance.
+    delete this;
   }
   virtual void didChooseFile(const WebVector<SelectedFileInfo>& file_names) {
     std::vector<std::string> files;
     for (size_t i = 0; i < file_names.size(); i++)
       files.push_back(file_names[i].path.utf8());
 
     file_chooser_->StoreChosenFiles(files);
+
+    // It is the responsibility of this method to delete the instance.
+    delete this;
   }
 
  private:
   scoped_refptr<PPB_FileChooser_Impl> file_chooser_;
 };
 
 }  // namespace
 
 PPB_FileChooser_Impl::PPB_FileChooser_Impl(
     PP_Instance instance,
@@ skipping 26 matching lines @@
 }
 
 PPB_FileChooser_API* PPB_FileChooser_Impl::AsPPB_FileChooser_API() {
   return this;
 }
 
 void PPB_FileChooser_Impl::StoreChosenFiles(
     const std::vector<std::string>& files) {
   next_chosen_file_index_ = 0;
 
+  // It is possible that |callback_| has been run: before the user takes action
+  // on the file chooser, the page navigates away and causes the plugin module
+  // (whose instance requested to show the file chooser) to be destroyed. In
+  // that case, |callback_| has been aborted when we get here.
+  if (!TrackedCallback::IsPending(callback_)) {
+    // To be cautious, reset our internal state.
+    output_.Reset();
+    chosen_files_.clear();
+    return;
+  }
+
   std::vector< scoped_refptr<Resource> > chosen_files;
   for (std::vector<std::string>::const_iterator it = files.begin();
        it != files.end(); ++it) {
 #if defined(OS_WIN)
     FilePath file_path(base::SysUTF8ToWide(*it));
 #else
     FilePath file_path(*it);
 #endif
 
     chosen_files.push_back(scoped_refptr<Resource>(
@@ skipping 124 matching lines @@
       continue;
     StringToLowerASCII(&mime_type);
     normalized_mime_type_list.push_back(WebString::fromUTF8(mime_type.data(),
                                                             mime_type.size()));
   }
   return normalized_mime_type_list;
 }
 
 }  // namespace ppapi
 }  // namespace webkit