Refactors DeviceOrientation to make it more extensible

content/browser/device_orientation/orientation_message_filter.cc

Index: content/browser/device_orientation/orientation_message_filter.cc
diff --git a/content/browser/device_orientation/orientation_message_filter.cc b/content/browser/device_orientation/orientation_message_filter.cc
index 11b1e06aea610bd7cceac3f21df397d3866beeac..4829b608c1d49dce2d14860d5565eaf150840427 100644
--- a/content/browser/device_orientation/orientation_message_filter.cc
+++ b/content/browser/device_orientation/orientation_message_filter.cc
@@ -29,10 +29,11 @@ class OrientationMessageFilter::ObserverDelegate
     // Will stop observing provider when destructed.
     ObserverDelegate(Provider* provider,
                      int render_view_id,
-                     IPC::Sender* sender);
+                     IPC::Sender* sender,
+                     DeviceData::DeviceDataType device_data_type);
 
     // From Provider::Observer.
-    virtual void OnOrientationUpdate(const Orientation& orientation);
+    virtual void OnDeviceDataUpdate(const DeviceData& device_data);
 
  private:
   friend class base::RefCounted<ObserverDelegate>;
@@ -46,21 +47,24 @@ class OrientationMessageFilter::ObserverDelegate
 };
 
 OrientationMessageFilter::ObserverDelegate::ObserverDelegate(Provider* provider,
-                                                  int render_view_id,
-                                                  IPC::Sender* sender)
-    : provider_(provider),
-      render_view_id_(render_view_id),
-      sender_(sender) {
+    int render_view_id, IPC::Sender* sender,
+    DeviceData::DeviceDataType device_data_type)
+  : provider_(provider),
+    render_view_id_(render_view_id),
+    sender_(sender) {
   provider_->AddObserver(this);
+  device_data_type_ = device_data_type;
 }
 
 OrientationMessageFilter::ObserverDelegate::~ObserverDelegate() {
   provider_->RemoveObserver(this);
 }
 
-void OrientationMessageFilter::ObserverDelegate::OnOrientationUpdate(
-    const Orientation& orientation) {
+void OrientationMessageFilter::ObserverDelegate::OnDeviceDataUpdate(
+    const DeviceData& device_data) {
   DeviceOrientationMsg_Updated_Params params;
+  const Orientation& orientation = static_cast<const Orientation&>(device_data);
+
   params.can_provide_alpha = orientation.can_provide_alpha();
   params.alpha = orientation.alpha();
   params.can_provide_beta = orientation.can_provide_beta();
@@ -92,8 +96,7 @@ void OrientationMessageFilter::OnStartUpdating(int render_view_id) {
     provider_ = Provider::GetInstance();
 
   observers_map_[render_view_id] = new ObserverDelegate(provider_,
-                                                        render_view_id,
-                                                        this);
+      render_view_id, this, DeviceData::kDeviceOrientationData);
 }
 
 void OrientationMessageFilter::OnStopUpdating(int render_view_id) {