Stop firing orientationchange events at pages that are not visible

Source/modules/screen_orientation/ScreenOrientationController.h

Index: Source/modules/screen_orientation/ScreenOrientationController.h
diff --git a/Source/modules/screen_orientation/ScreenOrientationController.h b/Source/modules/screen_orientation/ScreenOrientationController.h
index 5bc56f45f991c8450fbd150323310d990e5c08ec..5c5b571c91073d290f2345978749de3c6bcbb626 100644
--- a/Source/modules/screen_orientation/ScreenOrientationController.h
+++ b/Source/modules/screen_orientation/ScreenOrientationController.h
@@ -6,13 +6,14 @@
 #define ScreenOrientationController_h
 
 #include "core/dom/DocumentSupplementable.h"
+#include "core/page/PageLifecycleObserver.h"
 #include "public/platform/WebScreenOrientationType.h"
 
 namespace WebCore {
 
 class FrameView;
 
-class ScreenOrientationController FINAL : public NoBaseWillBeGarbageCollected<ScreenOrientationController>, public DocumentSupplement {
+class ScreenOrientationController FINAL : public NoBaseWillBeGarbageCollected<ScreenOrientationController>, public DocumentSupplement, public PageLifecycleObserver {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ScreenOrientationController);
 public:
     virtual ~ScreenOrientationController();
@@ -27,7 +28,11 @@ private:
     explicit ScreenOrientationController(Document&);
     static blink::WebScreenOrientationType computeOrientation(FrameView*);
 
+    // Inherited from PageLifecycleObserver.
+    virtual void pageVisibilityChanged() OVERRIDE;
+
     Document& m_document;
+    blink::WebScreenOrientationType m_lastVisibleOrientation;

[mlamouri (slow - plz ping), 2014/05/28 14:05:33]

Hmm, with your current implementation, this ought to be called
m_overrideOrientation given that you use that variable to also mark that the
current orientation should be ignored. More later.

[Inactive, 2014/05/28 15:27:28]

Done.

 };
 
 } // namespace WebCore