Remove refcounting from SavePackage.

content/browser/web_contents/web_contents_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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/histogram.h"
 #include "base/process/process.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 2720 matching lines @@
     RecordDownloadSource(INITIATED_BY_SAVE_PACKAGE_ON_NON_HTML);
     SaveFrame(GetLastCommittedURL(), Referrer());
     return;
   }
 
   Stop();
 
   // Create the save package and possibly prompt the user for the name to save
   // the page as. The user prompt is an asynchronous operation that runs on
   // another thread.
-  save_package_ = new SavePackage(this);
+  save_package_ = base::WrapUnique(new SavePackage(this));

[asanka, 2016/06/06 18:55:09]

Here and elsewhere:

Assigning a unique_ptr and ref_ptr confers entirely different lifetime
semantics. Previously, the old SavePackage will live long enough for the child
operations to complete due to the references held on it by the posted tasks etc.

Now, the old SavePackage is immediately destroyed when the new SavePackage is
assigned here. This makes all the Unretained() references in this CL to become
unsafe. The SP can go away pretty much at any point. You'll need to account for
those, perhaps by figuring out what the proper semantics should be for an old SP
when a new one is initiated.

   save_package_->GetSaveInfo();
 }
 
 // Used in automated testing to bypass prompting the user for file names.
 // Instead, the names and paths are hard coded rather than running them through
 // file name sanitation and extension / mime checking.
 bool WebContentsImpl::SavePage(const base::FilePath& main_file,
                                const base::FilePath& dir_path,
                                SavePageType save_type) {
   // Stop the page from navigating.
   Stop();
 
-  save_package_ = new SavePackage(this, save_type, main_file, dir_path);
+  save_package_ =
+      base::WrapUnique(new SavePackage(this, save_type, main_file, dir_path));
   return save_package_->Init(SavePackageDownloadCreatedCallback());
 }
 
 void WebContentsImpl::SaveFrame(const GURL& url,
                                 const Referrer& referrer) {
   SaveFrameWithHeaders(url, referrer, std::string());
 }
 
 void WebContentsImpl::SaveFrameWithHeaders(const GURL& url,
                                            const Referrer& referrer,
@@ skipping 2289 matching lines @@
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 void WebContentsImpl::SetJavaScriptDialogManagerForTesting(
     JavaScriptDialogManager* dialog_manager) {
   dialog_manager_ = dialog_manager;
 }
 
 }  // namespace content