Implement the Blink part of the Device Motion API.

Source/core/page/DOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1519 matching lines @@
             document->didAddTouchEventHandler(document);
         else if (eventType == eventNames().storageEvent)
             didAddStorageEventListener(this);
     }
 
     if (eventType == eventNames().unloadEvent)
         addUnloadEventListener(this);
     else if (eventType == eventNames().beforeunloadEvent && allowsBeforeUnloadListeners(this))
         addBeforeUnloadEventListener(this);
     else if (eventType == eventNames().devicemotionEvent && RuntimeEnabledFeatures::deviceMotionEnabled()) {
-        if (DeviceMotionController* controller = DeviceMotionController::from(page()))
-            controller->addDeviceEventListener(this);
+        if (DeviceMotionController* controller = DeviceMotionController::from(document()))

[Peter Beverloo, 2013/05/08 13:15:01]

I think it's confusing that you're passing document() here, while the
"devicemotion" event is available on the window object and has no relationship
to the document at all.

You supplement the device motion controller on ScriptExecutionContext, which is
a parent class of Document.  I don't think the DeviceMotionController should
know about Document at all, and we can instead just pass
DOMWindow::scriptExecutionContext().

The passed SEC will be identical to the one you're passing now so there won't be
any functional change, but I do think it's much cleaner.

[timvolodine, 2013/05/09 10:08:28]

hmm, the document is actually needed to dispatch the event to the window, I
haven't found any domWindow() method on the SEC.

[Peter Beverloo, 2013/05/09 11:31:38]

Right.  Now that we're no longer storing the DOMWindow in a RefPtr, I think it
would be fine to store a pointer to the DOMWindow instead of a pointer to
Document in DeviceMotionController.  You can get the script execution context
(activeDOMObjectsAre{Stopped,Suspended} et al) from DOMWindow as well.

Since the ScriptExecutionContext is owned by the DOMWindow this should be fine
in terms of lifetime as well.  What do you think?

+            controller->startUpdating();
     } else if (eventType == eventNames().deviceorientationEvent && RuntimeEnabledFeatures::deviceOrientationEnabled()) {
         if (DeviceOrientationController* controller = DeviceOrientationController::from(page()))
             controller->addDeviceEventListener(this);
     }
 
     return true;
 }
 
 bool DOMWindow::removeEventListener(const AtomicString& eventType, EventListener* listener, bool useCapture)
 {
     if (!EventTarget::removeEventListener(eventType, listener, useCapture))
         return false;
 
     if (Document* document = this->document()) {
         if (eventType == eventNames().mousewheelEvent)
             document->didRemoveWheelEventHandler();
         else if (eventNames().isTouchEventType(eventType))
             document->didRemoveTouchEventHandler(document);
     }
 
     if (eventType == eventNames().unloadEvent)
         removeUnloadEventListener(this);
     else if (eventType == eventNames().beforeunloadEvent && allowsBeforeUnloadListeners(this))
         removeBeforeUnloadEventListener(this);
     else if (eventType == eventNames().devicemotionEvent) {
-        if (DeviceMotionController* controller = DeviceMotionController::from(page()))
-            controller->removeDeviceEventListener(this);
+        if (DeviceMotionController* controller = DeviceMotionController::from(document()))
+            controller->stopUpdating();
     } else if (eventType == eventNames().deviceorientationEvent) {
         if (DeviceOrientationController* controller = DeviceOrientationController::from(page()))
             controller->removeDeviceEventListener(this);
     }
 
     return true;
 }
 
 void DOMWindow::dispatchLoadEvent()
 {
@@ skipping 34 matching lines @@
 
     InspectorInstrumentation::didDispatchEventOnWindow(cookie);
 
     return result;
 }
 
 void DOMWindow::removeAllEventListeners()
 {
     EventTarget::removeAllEventListeners();
 
-    if (DeviceMotionController* controller = DeviceMotionController::from(page()))
-        controller->removeAllDeviceEventListeners(this);
+    if (DeviceMotionController* controller = DeviceMotionController::from(document()))
+        controller->stopUpdating();
     if (DeviceOrientationController* controller = DeviceOrientationController::from(page()))
-        controller->removeAllDeviceEventListeners(this);
+        controller->removeDeviceEventListener(this);
     if (Document* document = this->document())
         document->didRemoveEventTargetNode(document);
 
     removeAllUnloadEventListeners(this);
     removeAllBeforeUnloadEventListeners(this);
 }
 
 void DOMWindow::captureEvents()
 {
     // Not implemented.
@@ skipping 248 matching lines @@
     WindowFeatures windowFeatures(dialogFeaturesString, screenAvailableRect(m_frame->view()));
     Frame* dialogFrame = createWindow(urlString, emptyAtom, windowFeatures,
         activeWindow, firstFrame, m_frame, function, functionContext);
     if (!dialogFrame)
         return;
     UserGestureIndicatorDisabler disabler;
     dialogFrame->page()->chrome()->runModal();
 }
 
 } // namespace WebCore