Remove content dependency from TransportSecurityPersister.

chrome/browser/net/transport_security_persister.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.
 
 // TransportSecurityState maintains an in memory database containing the
 // list of hosts that currently have transport security enabled. This
 // singleton object deals with writing that data out to disk as needed and
 // loading it at startup.
 
 // At startup we need to load the transport security state from the
 // disk. For the moment, we don't want to delay startup for this load, so we
 // let the TransportSecurityState run for a while without being loaded.
 // This means that it's possible for pages opened very quickly not to get the
 // correct transport security information.
 //
-// To load the state, we schedule a Task on the file thread which loads,
+// To load the state, we schedule a Task on file_task_runner, which
 // deserializes and configures the TransportSecurityState.
 //
 // The TransportSecurityState object supports running a callback function
 // when it changes. This object registers the callback, pointing at itself.
 //
 // TransportSecurityState calls...
 // TransportSecurityPersister::StateIsDirty
 //   since the callback isn't allowed to block or reenter, we schedule a Task
-//   on the file thread after some small amount of time
+//   on the file task runner after some small amount of time
 //
 // ...
 //
 // TransportSecurityPersister::SerializeState
 //   copies the current state of the TransportSecurityState, serializes
 //   and writes to disk.
 
 #ifndef CHROME_BROWSER_NET_TRANSPORT_SECURITY_PERSISTER_H_
 #define CHROME_BROWSER_NET_TRANSPORT_SECURITY_PERSISTER_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/files/important_file_writer.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "net/http/transport_security_state.h"
 
-// Reads and updates on-disk TransportSecurity state.
-// Must be created, used and destroyed only on the IO thread.
+namespace base {
+class SequencedTaskRunner;
+}
+
+// Reads and updates on-disk TransportSecurity state. Clients of this class
+// should create, destroy, and call into it from one thread.
+//
+// file_task_runner is the task runner this class should use internally to
+// perform file IO, and can optionally be associated with a different thread.
 class TransportSecurityPersister
     : public net::TransportSecurityState::Delegate,
       public base::ImportantFileWriter::DataSerializer {
  public:
   TransportSecurityPersister(net::TransportSecurityState* state,
                              const base::FilePath& profile_path,
+                             base::SequencedTaskRunner* file_task_runner,
                              bool readonly);
   virtual ~TransportSecurityPersister();
 
   // Called by the TransportSecurityState when it changes its state.
   virtual void StateIsDirty(net::TransportSecurityState*) OVERRIDE;
 
   // ImportantFileWriter::DataSerializer:
   //
   // Serializes |transport_security_state_| into |*output|. Returns true if
   // all DomainStates were serialized correctly.
@@ skipping 26 matching lines @@
   virtual bool SerializeData(std::string* data) OVERRIDE;
 
   // Clears any existing non-static entries, and then re-populates
   // |transport_security_state_|.
   //
   // Sets |*dirty| to true if the new state differs from the persisted
   // state; false otherwise.
   bool LoadEntries(const std::string& serialized, bool* dirty);
 
  private:
-  class Loader;
-
   // Populates |state| from the JSON string |serialized|. Returns true if
   // all entries were parsed and deserialized correctly.
   //
   // Sets |*dirty| to true if the new state differs from the persisted
   // state; false otherwise.
   static bool Deserialize(const std::string& serialized,
                           bool* dirty,
                           net::TransportSecurityState* state);
 
   void CompleteLoad(const std::string& state);
 
   net::TransportSecurityState* transport_security_state_;
 
   // Helper for safely writing the data.
   base::ImportantFileWriter writer_;
 
+  scoped_refptr<base::SequencedTaskRunner> foreground_runner_;
+  scoped_refptr<base::SequencedTaskRunner> background_runner_;
+
   // Whether or not we're in read-only mode.
   const bool readonly_;
 
   base::WeakPtrFactory<TransportSecurityPersister> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TransportSecurityPersister);
 };
 
 #endif  // CHROME_BROWSER_NET_TRANSPORT_SECURITY_PERSISTER_H_