Add start/stop listening Platform methods for Screen Orientation.

Source/modules/screen_orientation/ScreenOrientation.cpp

Index: Source/modules/screen_orientation/ScreenOrientation.cpp
diff --git a/Source/modules/screen_orientation/ScreenOrientation.cpp b/Source/modules/screen_orientation/ScreenOrientation.cpp
index d8e40ed08b5a21b4b8042667a1b58c3352577fe7..05aefe438599e13ec765d731da48e9590d50108b 100644
--- a/Source/modules/screen_orientation/ScreenOrientation.cpp
+++ b/Source/modules/screen_orientation/ScreenOrientation.cpp
@@ -14,6 +14,7 @@
 #include "modules/EventTargetModules.h"
 #include "modules/screen_orientation/LockOrientationCallback.h"
 #include "modules/screen_orientation/ScreenOrientationController.h"
+#include "public/platform/Platform.h"
 #include "public/platform/WebScreenOrientationType.h"
 
 // This code assumes that WebScreenOrientationType values are included in WebScreenOrientationLockType.
@@ -107,10 +108,13 @@ ScreenOrientation::ScreenOrientation(LocalFrame* frame)
     , m_angle(0)
 {
     ScriptWrappable::init(this);
+
+    blink::Platform::current()->startScreenOrientationListening();
 }
 
 ScreenOrientation::~ScreenOrientation()
 {
+    blink::Platform::current()->stopScreenOrientationListening();

[Michael van Ouwerkerk, 2014/07/17 10:36:27]

Shouldn't this also be called when page visibility changes to !visible? This
could go in a followup patch if you prefer, but I think you could still add it.

 }
 
 const WTF::AtomicString& ScreenOrientation::interfaceName() const