[iOS] Upstream iOS geolocation code

ios/chrome/browser/geolocation/location_manager.h

+// Copyright 2013 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 IOS_CHROME_BROWSER_GEOLOCATION_LOCATION_MANAGER_H_
+#define IOS_CHROME_BROWSER_GEOLOCATION_LOCATION_MANAGER_H_
+
+#import <CoreLocation/CoreLocation.h>
+#import <Foundation/Foundation.h>
+
+@class LocationManager;
+
+// Defines the methods to be implemented by a delegate of a LocationManager
+// instance.
+@protocol LocationManagerDelegate
+
+// Notifies the delegate that the application's authorization status changed.
+- (void)locationManagerDidChangeAuthorizationStatus:
+        (LocationManager*)locationManager;
+
+@end
+
+// Manages fetching and updating the current device location.
+@interface LocationManager : NSObject
+
+// The application’s authorization status for using location services. This
+// proxies |[CLLocationManager authorizationStatus]|, so that we can write unit
+// tests for client classes by mocking this class.
+@property(nonatomic, readonly) CLAuthorizationStatus authorizationStatus;
+
+// Returns the most recently fetched location.
+@property(nonatomic, readonly) CLLocation* currentLocation;
+
+// The delegate object for this instance of LocationManager.
+@property(nonatomic, assign) id<LocationManagerDelegate> delegate;  // weak

[sdefresne, 2015/04/28 08:34:39]

nit: I think "weak" is implied by "assign" (vs "retain/copy") and thus the
comment redundant. If you want to keep it, I think it should be moved into the
comment above the property definition.

+
+// Boolean value indicating whether location services are enabled on the
+// device. This proxies |[CLLocationManager locationServicesEnabled]|, so that
+// we can write unit tests for client classes by mocking this class.
+@property(nonatomic, readonly) BOOL locationServicesEnabled;
+
+// Starts updating device location if needed.
+- (void)startUpdatingLocation;
+
+// Stops updating device location.
+- (void)stopUpdatingLocation;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_GEOLOCATION_LOCATION_MANAGER_H_