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

Source/modules/device_orientation/DeviceMotionDispatcher.cpp

Index: Source/modules/device_orientation/DeviceMotionDispatcher.cpp
diff --git a/Source/modules/device_orientation/DeviceMotionDispatcher.cpp b/Source/modules/device_orientation/DeviceMotionDispatcher.cpp
index de89684be386bcc2324134d2d1b1645c43024180..00efc88d654af576347692862def7ad2b7359c9c 100644
--- a/Source/modules/device_orientation/DeviceMotionDispatcher.cpp
+++ b/Source/modules/device_orientation/DeviceMotionDispatcher.cpp
@@ -34,6 +34,7 @@
 #include "modules/device_orientation/DeviceMotionController.h"
 #include "modules/device_orientation/DeviceMotionData.h"
 #include "public/platform/Platform.h"
+#include "wtf/TemporaryChange.h"
 
 namespace WebCore {
 
@@ -51,6 +52,16 @@
 {
 }
 
+void DeviceMotionDispatcher::addDeviceMotionController(DeviceMotionController* controller)
+{
+    addController(controller);
+}
+
+void DeviceMotionDispatcher::removeDeviceMotionController(DeviceMotionController* controller)
+{
+    removeController(controller);
+}
+
 void DeviceMotionDispatcher::startListening()
 {
     blink::Platform::current()->setDeviceMotionListener(this);
@@ -65,7 +76,19 @@
 void DeviceMotionDispatcher::didChangeDeviceMotion(const blink::WebDeviceMotionData& motion)
 {
     m_lastDeviceMotionData = DeviceMotionData::create(motion);
-    notifyControllers();
+
+    {
+        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<DeviceMotionController*>(m_controllers[i])->didChangeDeviceMotion(m_lastDeviceMotionData.get());
+        }
+    }
+
+    if (m_needsPurge)
+        purgeControllers();
 }
 
 DeviceMotionData* DeviceMotionDispatcher::latestDeviceMotionData()