Move core pieces of geolocation from chrome to content....

chrome/browser/geolocation/location_provider.h

-// Copyright (c) 2010 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.
-
-// A location provider provides position information from a particular source
-// (GPS, network etc). The GearsGeolocation object uses a set of location
-// providers to obtain a position fix.
-//
-// This file declares a base class to be used by all location providers.
-// Primarily, this class declares interface methods to be implemented by
-// derived classes.
-
-#ifndef CHROME_BROWSER_GEOLOCATION_LOCATION_PROVIDER_H_
-#define CHROME_BROWSER_GEOLOCATION_LOCATION_PROVIDER_H_
-#pragma once
-
-#include <map>
-#include "base/string16.h"
-#include "base/threading/non_thread_safe.h"
-
-class AccessTokenStore;
-struct Geoposition;
-class GURL;
-class URLRequestContextGetter;
-
-// The base class used by all location providers.
-class LocationProviderBase : public base::NonThreadSafe {
- public:
-  // Clients of the location provider must implement this interface. All call-
-  // backs to this interface will happen in the context of the thread on which
-  // the location provider was created.
-  class ListenerInterface {
-   public:
-    // Used to inform listener that a new position fix is available or that a
-    // fatal error has occurred. Providers should call this for new listeners
-    // as soon as a position is available.
-    virtual void LocationUpdateAvailable(LocationProviderBase* provider) = 0;
-
-   protected:
-    virtual ~ListenerInterface() {}
-  };
-
-  virtual ~LocationProviderBase();
-
-  // Registers a listener, which will be called back on
-  // ListenerInterface::LocationUpdateAvailable as soon as a position is
-  // available and again whenever a new position is available. Ref counts the
-  // listener to handle multiple calls to this method.
-  void RegisterListener(ListenerInterface* listener);
-  // Unregisters a listener. Unrefs the listener to handle multiple calls to
-  // this method. Once the ref count reaches zero, the listener is removed and
-  // once this method returns, no further calls to
-  // ListenerInterface::LocationUpdateAvailable will be made for this listener.
-  // It may block if a callback is in progress.
-  void UnregisterListener(ListenerInterface* listener);
-
-  // Interface methods
-  // StartProvider maybe called multiple times, e.g. to alter the
-  // |high_accuracy| setting. Returns false if a fatal error was encountered
-  // which prevented the provider from starting.
-  virtual bool StartProvider(bool high_accuracy) = 0;
-  virtual void StopProvider() = 0;
-  // Gets the current best position estimate.
-  virtual void GetPosition(Geoposition* position) = 0;
-  // Provides a hint to the provider that new location data is needed as soon
-  // as possible. Default implementation does nothing.
-  virtual void UpdatePosition() {}
-  // Delegated to the provider by GeolocationArbitrator. See the corresponding
-  // method on that class for more details.
-  virtual void OnPermissionGranted(const GURL& requesting_frame) {}
-
-  bool has_listeners() const;
-
- protected:
-  LocationProviderBase();
-
-  // Inform listeners that a new position or error is available, using
-  // LocationUpdateAvailable.
-  void UpdateListeners();
-
- private:
-  // The listeners registered to this provider. For each listener, we store a
-  // ref count.
-  typedef std::map<ListenerInterface*, int> ListenerMap;
-  ListenerMap listeners_;
-};
-
-// Factory functions for the various types of location provider to abstract
-// over the platform-dependent implementations.
-LocationProviderBase* NewNetworkLocationProvider(
-    AccessTokenStore* access_token_store,
-    URLRequestContextGetter* context,
-    const GURL& url,
-    const string16& access_token);
-LocationProviderBase* NewSystemLocationProvider();
-
-#endif  // CHROME_BROWSER_GEOLOCATION_LOCATION_PROVIDER_H_