Generalize and refactor DeviceSensorEvent* architecture to support multi-event type targets.

Source/modules/device_orientation/DeviceOrientationDispatcher.cpp

Index: Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
diff --git a/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp b/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
index ed73d039e8a2fe02e57b474002e88edfc65157d1..4c82b25aaa92041c0318862cf2a01268c79d3f62 100644
--- a/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
+++ b/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
@@ -34,7 +34,6 @@
 #include "modules/device_orientation/DeviceOrientationController.h"
 #include "modules/device_orientation/DeviceOrientationData.h"
 #include "public/platform/Platform.h"
-#include "wtf/TemporaryChange.h"
 
 namespace WebCore {
 
@@ -52,16 +51,6 @@ DeviceOrientationDispatcher::~DeviceOrientationDispatcher()
 {
 }
 
-void DeviceOrientationDispatcher::addDeviceOrientationController(DeviceOrientationController* controller)
-{
-    addController(controller);
-}
-
-void DeviceOrientationDispatcher::removeDeviceOrientationController(DeviceOrientationController* controller)
-{
-    removeController(controller);
-}
-
 void DeviceOrientationDispatcher::startListening()
 {
     blink::Platform::current()->setDeviceOrientationListener(this);
@@ -76,19 +65,7 @@ void DeviceOrientationDispatcher::stopListening()
 void DeviceOrientationDispatcher::didChangeDeviceOrientation(const blink::WebDeviceOrientationData& motion)
 {
     m_lastDeviceOrientationData = DeviceOrientationData::create(motion);
-
-    {
-        TemporaryChange<bool> changeIsDispatching(m_isDispatching, true);
-        // Don't fire controllers removed or added during event dispatch.
-        size_t size = m_controllers.size();
-        for (size_t i = 0; i < size; ++i) {
-            if (m_controllers[i])
-                static_cast<DeviceOrientationController*>(m_controllers[i])->didChangeDeviceOrientation(m_lastDeviceOrientationData.get());
-        }
-    }
-
-    if (m_needsPurge)
-        purgeControllers();
+    notifyControllers();
 }
 
 DeviceOrientationData* DeviceOrientationDispatcher::latestDeviceOrientationData()