Refactor WifiDataProviderChromeOs to implement WifiDataProviderImplBase directly.

content/browser/geolocation/device_data_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 device data provider provides data from the device that is used by a
 // NetworkLocationProvider to obtain a position fix. This data may be either
 // cell radio data or wifi data. For a given type of data, we use a singleton
 // instance of the device data provider, which is used by multiple
 // NetworkLocationProvider objects.
 //
@@ skipping 162 matching lines @@
 
 // See class DeviceDataProvider for the public client API.
 // DeviceDataProvider uses containment to hide platform-specific implementation
 // details from common code. This class provides common functionality for these
 // contained implementation classes. This is a modified pimpl pattern: this
 // class needs to be in the public header due to use of templating.
 template<typename DataType>
 class DeviceDataProviderImplBase : public DeviceDataProviderImplBaseHack {
  public:
   DeviceDataProviderImplBase()
-      : container_(NULL), client_loop_(MessageLoop::current()) {
+      : client_loop_(MessageLoop::current()), container_(NULL) {
     DCHECK(client_loop_);
   }
 
   virtual bool StartDataProvider() = 0;
   virtual void StopDataProvider() = 0;
   virtual bool GetData(DataType* data) = 0;
 
   // Sets the container of this class, which is of type DeviceDataProvider.
   // This is required to pass as a parameter when making the callback to
   // listeners.
@@ skipping 29 matching lines @@
     // Always make the nitofy callback via a posted task, se we can unwind
     // callstack here and make callback without causing client re-entrancy.
     client_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
         &DeviceDataProviderImplBase<DataType>::NotifyListenersInClientLoop));
   }
 
   bool CalledOnClientThread() const {
     return MessageLoop::current() == this->client_loop_;
   }
 
+  // Reference to the client's message loop, all callbacks and access to
+  // the listeners_ member should happen in this context.
+  MessageLoop* client_loop_;

[stevenjb, 2011/03/16 17:46:56]

We shouldn't expose this publicly if we only need to access it. Instead:
MessageLoop* client_loop() const { return client_loop_; }

[John Knottenbelt, 2011/03/16 18:20:14]

Done.

+
  private:
   void NotifyListenersInClientLoop() {
     DCHECK(CalledOnClientThread());
     // It's possible that all the listeners (and the container) went away
     // whilst this task was pending. This is fine; the loop will be a no-op.
     typename ListenersSet::const_iterator iter = listeners_.begin();
     while (iter != listeners_.end()) {
       ListenerInterface* listener = *iter;
       ++iter;  // Advance iter before callback, in case listener unregisters.
       listener->DeviceDataUpdateAvailable(container_);
     }
   }
 
   DeviceDataProvider<DataType>* container_;
 
-  // Reference to the client's message loop, all callbacks and access to
-  // the listeners_ member should happen in this context.
-  MessageLoop* client_loop_;
-
   ListenersSet listeners_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDataProviderImplBase);
 };
 
 typedef DeviceDataProviderImplBase<GatewayData> GatewayDataProviderImplBase;
 typedef DeviceDataProviderImplBase<RadioData> RadioDataProviderImplBase;
 typedef DeviceDataProviderImplBase<WifiData> WifiDataProviderImplBase;
 
 // A device data provider
@@ skipping 131 matching lines @@
 // static
 template<typename DataType>
 typename DeviceDataProvider<DataType>::ImplFactoryFunction
     DeviceDataProvider<DataType>::factory_function_ = DefaultFactoryFunction;
 
 typedef DeviceDataProvider<GatewayData> GatewayDataProvider;
 typedef DeviceDataProvider<RadioData> RadioDataProvider;
 typedef DeviceDataProvider<WifiData> WifiDataProvider;
 
 #endif  // CONTENT_BROWSER_GEOLOCATION_DEVICE_DATA_PROVIDER_H_