Remove refcounting from SavePackage.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index bfdda50f69c982a5208572a106e7b34157cfed2d..2eb1af27f255f93378d6b16cd270a83f02824c2e 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -14,6 +14,7 @@
 #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"
@@ -2754,7 +2755,7 @@ void WebContentsImpl::OnSavePage() {
   // 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();
 }
 
@@ -2767,7 +2768,8 @@ bool WebContentsImpl::SavePage(const base::FilePath& main_file,
   // 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());
 }