Merge Chromium src@r53293

Change-Id: Ia79acf8670f385cee48c45b0a75371d8e950af34

1 files changed, 147 insertions, 0 deletions

diff --git a/chrome/browser/geolocation/location_arbitrator.h b/chrome/browser/geolocation/location_arbitrator.h
new file mode 100644
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+++ b/chrome/browser/geolocation/location_arbitrator.h
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+// 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.
+
+#ifndef CHROME_BROWSER_GEOLOCATION_LOCATION_ARBITRATOR_H_
+#define CHROME_BROWSER_GEOLOCATION_LOCATION_ARBITRATOR_H_
+
+#include "base/string16.h"
+#include "base/time.h"
+#include "base/ref_counted.h"
+
+class AccessTokenStore;
+class GURL;
+class LocationProviderBase;
+class URLRequestContextGetter;
+struct Geoposition;
+
+// This is the main API to the geolocaiton subsystem. Typically the application
+// will hold a single instance of this class, and can register multiple
+// observers which will be notified of location updates. Underlying location
+// provider(s) will only be enabled whilst there is at least one observer
+// registered.
+// This class is responsible for handling updates from multiple underlying
+// providers and resolving them to a single 'best' location fix at any given
+// moment.
+class GeolocationArbitrator : public base::RefCounted<GeolocationArbitrator> {
+ public:
+  // Number of milliseconds newer a location provider has to be that it's worth
+  // switching to this location provider on the basis of it being fresher
+  // (regardles of relative accuracy). Public for tests.
+  static const int64 kFixStaleTimeoutMilliseconds;
+
+  // Defines a function that returns the current time.
+  typedef base::Time (*GetTimeNow)();
+
+  // Allows injection of factory methods for creating the location providers.
+  // RefCounted for simplicity of writing tests.
+  class ProviderFactory  : public base::RefCounted<ProviderFactory> {
+   public:
+    virtual LocationProviderBase* NewNetworkLocationProvider(
+        AccessTokenStore* access_token_store,
+        URLRequestContextGetter* context,
+        const GURL& url,
+        const string16& access_token) = 0;
+    virtual LocationProviderBase* NewGpsLocationProvider() = 0;
+
+   protected:
+    friend class base::RefCounted<ProviderFactory>;
+    virtual ~ProviderFactory();
+  };
+
+  // Creates and returns a new instance of the location arbitrator. Allows
+  // injection of dependencies, for testing.
+  static GeolocationArbitrator* Create(
+      AccessTokenStore* access_token_store,
+      URLRequestContextGetter* context_getter,
+      GetTimeNow get_time_now,
+      ProviderFactory* provider_factory);
+
+  // Gets a pointer to the singleton instance of the location arbitrator, which
+  // is in turn bound to the browser's global context objects. Ownership is NOT
+  // returned.
+  static GeolocationArbitrator* GetInstance();
+
+  class Delegate {
+   public:
+    // This will be called whenever the 'best available' location is updated,
+    // or when an error is encountered meaning no location data will be
+    // available in the forseeable future.
+    virtual void OnLocationUpdate(const Geoposition& position) = 0;
+
+   protected:
+    Delegate() {}
+    virtual ~Delegate() {}
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+  struct UpdateOptions {
+    UpdateOptions() : use_high_accuracy(false) {}
+    explicit UpdateOptions(bool high_accuracy)
+        : use_high_accuracy(high_accuracy) {}
+
+    // Given a map<ANYTHING, UpdateOptions> this function will iterate the map
+    // and collapse all the options found to a single instance that satisfies
+    // them all.
+    template <typename MAP>
+    static UpdateOptions Collapse(const MAP& options_map) {
+      for (typename MAP::const_iterator it = options_map.begin();
+           it != options_map.end(); ++it) {
+        if (it->second.use_high_accuracy)
+          return UpdateOptions(true);
+      }
+      return UpdateOptions(false);
+    }
+
+    bool use_high_accuracy;
+  };
+
+  // Must be called from the same thread as the arbitrator was created on.
+  // The update options passed are used as a 'hint' for the provider preferences
+  // for this particular observer, however the delegate could receive callbacks
+  // for best available locations from any active provider whilst it is
+  // registered.
+  // If an existing delegate is added a second time it's options are updated
+  // but only a single call to RemoveObserver() is required to remove it.
+  virtual void AddObserver(Delegate* delegate,
+                           const UpdateOptions& update_options) = 0;
+  // Remove a previously registered observer. No-op if not previously registered
+  // via AddObserver(). Returns true if the observer was removed.
+  virtual bool RemoveObserver(Delegate* delegate) = 0;
+
+  // Returns the current position estimate, or an uninitialized position
+  // if none is yet available. Once initialized, this will always match
+  // the most recent observer notification (via Delegate::OnLocationUpdate()).
+  virtual Geoposition GetCurrentPosition() = 0;
+
+  // Called everytime permission is granted to a page for using geolocation.
+  // This may either be through explicit user action (e.g. responding to the
+  // infobar prompt) or inferred from a persisted site permission.
+  // The arbitrator will inform all providers of this, which may in turn use
+  // this information to modify their internal policy.
+  virtual void OnPermissionGranted(const GURL& requesting_frame) = 0;
+
+  // Returns true if this arbitrator has received at least one call to
+  // OnPermissionGranted().
+  virtual bool HasPermissionBeenGranted() const = 0;
+
+  // For testing, a factory function can be set which will be used to create
+  // a specified test provider. Pass NULL to reset to the default behavior.
+  // For finer grained control, use class ProviderFactory instead.
+  // TODO(joth): Move all tests to use ProviderFactory and remove this.
+  typedef LocationProviderBase* (*LocationProviderFactoryFunction)(void);
+  static void SetProviderFactoryForTest(
+      LocationProviderFactoryFunction factory_function);
+
+ protected:
+  friend class base::RefCounted<GeolocationArbitrator>;
+  GeolocationArbitrator();
+  // RefCounted object; no not delete directly.
+  virtual ~GeolocationArbitrator();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GeolocationArbitrator);
+};
+
+#endif  // CHROME_BROWSER_GEOLOCATION_LOCATION_ARBITRATOR_H_