Refactors DeviceOrientation to make it more extensible

content/browser/device_orientation/observer_delegate.h

Index: content/browser/device_orientation/observer_delegate.h
diff --git a/content/browser/device_orientation/observer_delegate.h b/content/browser/device_orientation/observer_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..dfaa841e945c300691cd375206eeb6dba64c08fc
--- /dev/null
+++ b/content/browser/device_orientation/observer_delegate.h
@@ -0,0 +1,45 @@
+// Copyright (c) 2012 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 CONTENT_BROWSER_DEVICE_ORIENTATION_OBSERVER_DELEGATE_H_
+#define CONTENT_BROWSER_DEVICE_ORIENTATION_OBSERVER_DELEGATE_H_
+
+#include "content/browser/device_orientation/device_data.h"
+#include "content/browser/device_orientation/provider.h"
+
+namespace IPC {
+class Sender;
+}
+
+namespace device_orientation {
+
+class ObserverDelegate
+    : public base::RefCounted<ObserverDelegate>, public Provider::Observer {
+ public:
+  // Create ObserverDelegate that observes provider and forwards updates to
+  // render_view_id.
+  // Will stop observing provider when destructed.
+  ObserverDelegate(DeviceData::Type device_data_type, Provider* provider,
+                   int render_view_id, IPC::Sender* sender);
+
+  // From Provider::Observer.
+  virtual void OnDeviceDataUpdate(const DeviceData* device_data,
+                                  DeviceData::Type device_data_type) OVERRIDE;
+
+ private:
+  static DeviceData* EmptyDeviceData(DeviceData::Type type);
+
+  friend class base::RefCounted<ObserverDelegate>;
+  virtual ~ObserverDelegate();
+
+  scoped_refptr<Provider> provider_;
+  int render_view_id_;
+  IPC::Sender* sender_;  // Weak pointer.
+
+  DISALLOW_COPY_AND_ASSIGN(ObserverDelegate);
+};
+
+}  // namespace device_orientation
+
+#endif  // CONTENT_BROWSER_DEVICE_ORIENTATION_OBSERVER_DELEGATE_H_