Re-revert of "Remove SSLClientAuthHandler's RDH dependency." (https://codereview.chromium.org/596873002)

Reason for revert:
Causes browser crash if URL request is cancelled during client cert loading.

This is a reland of https://codereview.chromium.org/766463002/ which reverted
https://codereview.chromium.org/596873002. The revert was reverted because it
introduced a memory leak.

The source of this memory leak was a reference cycle in
chrome/browser/chromeos/net/client_cert_filter_chromeos.cc whose fix is
included in this CL. If InitIfSlotsAvailable returns true (synchronously), the
callback should not be retained. This was not a problem before as the code in
question was introduced after https://codereview.chromium.org/596873002 which
unrefcounted an object.

After this is merged into M-40, https://codereview.chromium.org/596873002
should be reworked with the crash fixed as this reference cycle is too subtle
and the object really needn't be reference-counted.

TBR=mmenke@chromium.org,benm@chromium.org,jam@chromium.org

BUG=422765, 427844, 376003

Review URL: https://codereview.chromium.org/773003004

Cr-Commit-Position: refs/heads/master@{#306649}

1 files changed, 40 insertions, 18 deletions

diff --git a/content/browser/ssl/ssl_client_auth_handler.h b/content/browser/ssl/ssl_client_auth_handler.h
index f95e65d..b848d54 100644
--- a/content/browser/ssl/ssl_client_auth_handler.h
+++ b/content/browser/ssl/ssl_client_auth_handler.h
@@ -6,57 +6,79 @@
 #define CONTENT_BROWSER_SSL_SSL_CLIENT_AUTH_HANDLER_H_
 
 #include "base/basictypes.h"
-#include "base/callback.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
+#include "base/sequenced_task_runner_helpers.h"
+#include "content/common/content_export.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/ssl/ssl_cert_request_info.h"
 
 namespace net {
 class ClientCertStore;
+class HttpNetworkSession;
 class URLRequest;
 class X509Certificate;
 }  // namespace net
 
 namespace content {
 
+class ResourceContext;
+
 // This class handles the approval and selection of a certificate for SSL client
-// authentication by the user. Should only be used on the IO thread. If the
-// SSLClientAuthHandler is destroyed before the certificate is selected, the
-// selection is canceled and the callback never called.
-class SSLClientAuthHandler {
+// authentication by the user.
+// It is self-owned and deletes itself when the UI reports the user selection or
+// when the net::URLRequest is cancelled.
+class CONTENT_EXPORT SSLClientAuthHandler
+    : public base::RefCountedThreadSafe<
+          SSLClientAuthHandler, BrowserThread::DeleteOnIOThread> {
  public:
-  typedef base::Callback<void(net::X509Certificate*)> CertificateCallback;
-
   SSLClientAuthHandler(scoped_ptr<net::ClientCertStore> client_cert_store,
                        net::URLRequest* request,
-                       net::SSLCertRequestInfo* cert_request_info,
-                       const CertificateCallback& callback);
-  ~SSLClientAuthHandler();
+                       net::SSLCertRequestInfo* cert_request_info);
 
   // Selects a certificate and resumes the URL request with that certificate.
+  // Should only be called on the IO thread.
   void SelectCertificate();
 
+  // Invoked when the request associated with this handler is cancelled.
+  // Should only be called on the IO thread.
+  void OnRequestCancelled();
+
+  // Calls DoCertificateSelected on the I/O thread.
+  // Called on the UI thread after the user has made a selection (which may
+  // be long after DoSelectCertificate returns, if the UI is modeless/async.)
+  void CertificateSelected(net::X509Certificate* cert);
+
+ protected:
+  virtual ~SSLClientAuthHandler();
+
  private:
+  friend class base::RefCountedThreadSafe<
+      SSLClientAuthHandler, BrowserThread::DeleteOnIOThread>;
+  friend class BrowserThread;
+  friend class base::DeleteHelper<SSLClientAuthHandler>;
+
   // Called when ClientCertStore is done retrieving the cert list.
   void DidGetClientCerts();
 
-  // Called when the user has selected a cert.
-  void CertificateSelected(net::X509Certificate* cert);
+  // Notifies that the user has selected a cert.
+  // Called on the IO thread.
+  void DoCertificateSelected(net::X509Certificate* cert);
+
+  // Selects a client certificate on the UI thread.
+  void DoSelectCertificate(int render_process_host_id,
+                           int render_frame_host_id);
 
   // The net::URLRequest that triggered this client auth.
   net::URLRequest* request_;
 
+  // The HttpNetworkSession |request_| is associated with.
+  const net::HttpNetworkSession* http_network_session_;
+
   // The certs to choose from.
   scoped_refptr<net::SSLCertRequestInfo> cert_request_info_;
 
   scoped_ptr<net::ClientCertStore> client_cert_store_;
 
-  // The callback to call when the certificate is selected.
-  CertificateCallback callback_;
-
-  base::WeakPtrFactory<SSLClientAuthHandler> weak_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(SSLClientAuthHandler);
 };