Refactors DeviceOrientation to make it more extensible

content/browser/device_orientation/orientation.h

Index: content/browser/device_orientation/orientation.h
diff --git a/content/browser/device_orientation/orientation.h b/content/browser/device_orientation/orientation.h
index 543ff0bc7f3026b1048fd45bad12dc5a05129332..770b8dc32962b7d362aa12322fb25815a58fba2e 100644
--- a/content/browser/device_orientation/orientation.h
+++ b/content/browser/device_orientation/orientation.h
@@ -5,8 +5,12 @@
 #ifndef CONTENT_BROWSER_DEVICE_ORIENTATION_ORIENTATION_H_
 #define CONTENT_BROWSER_DEVICE_ORIENTATION_ORIENTATION_H_
 
+#include "base/compiler_specific.h"
+#include "content/browser/device_orientation/device_data.h"
+
 namespace device_orientation {
-class Orientation {
+
+class Orientation : public DeviceData {
  public:
   // alpha, beta, gamma and absolute are the rotations around the axes as
   // specified in http://dev.w3.org/geo/api/spec-source-orientation.html
@@ -15,42 +19,17 @@ class Orientation {
   // for that variable.
 
   Orientation()
-      : alpha_(0),
-        beta_(0),
-        gamma_(0),
-        absolute_(false),
-        can_provide_alpha_(false),
+      : can_provide_alpha_(false),
         can_provide_beta_(false),
         can_provide_gamma_(false),
         can_provide_absolute_(false) {
   }
-  Orientation(const Orientation& orientation)
-      : alpha_(orientation.alpha()),
-        beta_(orientation.beta()),
-        gamma_(orientation.gamma()),
-        absolute_(orientation.absolute()),
-        can_provide_alpha_(orientation.can_provide_alpha()),
-        can_provide_beta_(orientation.can_provide_beta()),
-        can_provide_gamma_(orientation.can_provide_gamma()),
-        can_provide_absolute_(orientation.can_provide_absolute()) {
-  }
-  void operator=(const Orientation& source) {
-    alpha_ = source.alpha();
-    beta_ = source.beta();
-    gamma_ = source.gamma();
-    absolute_ = source.absolute();
-    can_provide_alpha_ = source.can_provide_alpha();
-    can_provide_beta_ = source.can_provide_beta();
-    can_provide_gamma_ = source.can_provide_gamma();
-    can_provide_absolute_ = source.can_provide_absolute();
-  }
-
-  static Orientation Empty() { return Orientation(); }
 
-  bool is_empty() const {
-    return !can_provide_alpha_ && !can_provide_beta_ && !can_provide_gamma_
-        && !can_provide_absolute_;
-  }
+  virtual DeviceData* Clone() const OVERRIDE;
+  virtual bool IsEmpty() const OVERRIDE;
+  virtual bool SignificantlyDifferentFrom(
+      const DeviceData& other) const OVERRIDE;
+  virtual IPC::Message* CreateIPCMessage(int render_view_id) const OVERRIDE;
 
   void set_alpha(double alpha) {
     can_provide_alpha_ = true;