Make SSLErrorHandler UI-thread-only and not-refcounted

content/browser/ssl/ssl_error_handler.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 CONTENT_BROWSER_SSL_SSL_ERROR_HANDLER_H_
 #define CONTENT_BROWSER_SSL_SSL_ERROR_HANDLER_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/common/resource_type.h"
 #include "net/ssl/ssl_info.h"
 #include "url/gurl.h"
 
 namespace net {
 class URLRequest;
 }  // namespace net
 
 namespace content {
 
 class ResourceDispatcherHostImpl;
 class SSLManager;
 class WebContents;
 
-// An SSLErrorHandler carries information from the IO thread to the UI thread
-// and is dispatched to the appropriate SSLManager when it arrives on the
-// UI thread.  Subclasses should override the OnDispatched/OnDispatchFailed
-// methods to implement the actions that should be taken on the UI thread.
-// These methods can call the different convenience methods ContinueRequest/
-// CancelRequest to perform any required action on the net::URLRequest the
-// ErrorHandler was created with.
-//
-// IMPORTANT NOTE:
-//
-//   If you are not doing anything in OnDispatched/OnDispatchFailed, make sure
-//   you call TakeNoAction().  This is necessary for ensuring the instance is
-//   not leaked.
-//
-class SSLErrorHandler : public base::RefCountedThreadSafe<SSLErrorHandler> {
+// SSLErrorHandler is the UI-thread class for handling SSL certificate
+// errors. Users of this class can call CancelRequest(),
+// ContinueRequest(), or DenyRequest() when a decision about how to
+// handle the error has been made. Users of this class must
+// call exactly one of those methods exactly once.
+class SSLErrorHandler {
  public:
-  // Delegate functions must be called from IO thread. Finally,
-  // CancelSSLRequest() or ContinueSSLRequest() will be called after
-  // SSLErrorHandler makes a decision on the SSL error.
+  // SSLErrorHandler's delegate lives on the IO thread, and thus these
+  // delegate methods must be called on the IO thread only.
   class CONTENT_EXPORT Delegate {
    public:
     // Called when SSLErrorHandler decides to cancel the request because of
     // the SSL error.
     virtual void CancelSSLRequest(int error, const net::SSLInfo* ssl_info) = 0;
 
     // Called when SSLErrorHandler decides to continue the request despite the
     // SSL error.
     virtual void ContinueSSLRequest() = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
-  // Construct on the IO thread.
-  SSLErrorHandler(const base::WeakPtr<Delegate>& delegate,
+  SSLErrorHandler(WebContents* web_contents,
+                  const base::WeakPtr<Delegate>& delegate,
                   ResourceType resource_type,
                   const GURL& url,
                   const net::SSLInfo& ssl_info,
                   bool fatal);
 
-  // Find the appropriate SSLManager for the net::URLRequest and begin handling
-  // this error.
-  //
-  // Call on UI thread.
-  void Dispatch(const base::Callback<WebContents*(void)>& web_contents_getter);
+  virtual ~SSLErrorHandler();
 
-  // These accessors are available on either thread
   const net::SSLInfo& ssl_info() const { return ssl_info_; }
+
+  const GURL& request_url() const { return request_url_; }
+
+  ResourceType resource_type() const { return resource_type_; }
+
+  WebContents* web_contents() const { return web_contents_; }
+
   int cert_error() const { return cert_error_; }
+
   bool fatal() const { return fatal_; }
-  const GURL& request_url() const { return request_url_; }
-  ResourceType resource_type() const { return resource_type_; }
 
   // Cancels the associated net::URLRequest.
   CONTENT_EXPORT void CancelRequest();
 
   // Continue the net::URLRequest ignoring any previous errors.  Note that some
   // errors cannot be ignored, in which case this will result in the request
   // being canceled.
   void ContinueRequest();
 
   // Cancels the associated net::URLRequest and mark it as denied.  The renderer
   // processes such request in a special manner, optionally replacing them
   // with alternate content (typically frames content is replaced with a
   // warning message).
   void DenyRequest();
 
-  // Does nothing on the net::URLRequest but ensures the current instance ref
-  // count is decremented appropriately.
-  void TakeNoAction();
-
-  // Returns the manager associated with this SSLErrorHandler.
-  // Should only be accessed on the UI thread.
-  SSLManager* GetManager() const;
-
  private:
-  friend class base::RefCountedThreadSafe<SSLErrorHandler>;
-
-  virtual ~SSLErrorHandler();
-
-  virtual void OnDispatchFailed();
-
-  // Can use the manager_ member.
-  virtual void OnDispatched();
-
-  // Should only be accessed on the UI thread.
-  SSLManager* manager_;  // Our manager.
-
-  // The delegate we are associated with.
+  // This must not be dereferenced on the UI thread. SSLErrorHandler
+  // simply holds on to the reference to be passed back to the IO thread
+  // to enact a decision about the error once one has been made.
   base::WeakPtr<Delegate> delegate_;
 
-  // Completes the CancelRequest operation on the IO thread.
-  // Call on the IO thread.
-  void CompleteCancelRequest(int error);
-
-  // Completes the ContinueRequest operation on the IO thread.
-  //
-  // Call on the IO thread.
-  void CompleteContinueRequest();
-
-  // Derefs this instance.
-  // Call on the IO thread.
-  void CompleteTakeNoAction();
-
-  // A flag to make sure we notify the net::URLRequest exactly once.
-  // Should only be accessed on the IO thread
-  bool request_has_been_notified_;
-
-  // The below read-only members may be accessed on any thread.
-
-  // The URL that we requested.
+  // The URL for the request that generated the error.
   const GURL request_url_;
 
   // What kind of resource is associated with the request that generated
   // the error.
   const ResourceType resource_type_;
 
-  // The SSLInfo associated with the request that generated the error.
+  // The net::SSLInfo associated with the request that generated the error.
   const net::SSLInfo ssl_info_;
 
-  // The net error code that occurred on the request.
+  // A net error code describing the error that occurred.
   const int cert_error_;
 
   // True if the error is from a host requiring certificate errors to be fatal.
   const bool fatal_;
 
+  // The WebContents associated with the request that generated the error.
+  WebContents* web_contents_;
+
   DISALLOW_COPY_AND_ASSIGN(SSLErrorHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SSL_SSL_ERROR_HANDLER_H_