[DevTools] Implement screen orientation override.

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 f77d1bc21695efb6b65f5f68bd546cfe8753a084..03a042b70bbeb685fc77235373af95a83ab3c603 100644
--- a/Source/modules/screen_orientation/ScreenOrientationController.h
+++ b/Source/modules/screen_orientation/ScreenOrientationController.h
@@ -36,6 +36,9 @@ public:
     void lock(WebScreenOrientationLockType, WebLockOrientationCallback*);
     void unlock();
 
+    void setOverride(WebScreenOrientationType, unsigned short angle);
+    void clearOverride();
+
     static void provideTo(LocalFrame&, WebScreenOrientationClient*);
     static ScreenOrientationController* from(LocalFrame&);
     static const char* supplementName();
@@ -68,6 +71,9 @@ private:
     PersistentWillBeMember<ScreenOrientation> m_orientation;
     WebScreenOrientationClient* m_client;
     Timer<ScreenOrientationController> m_dispatchEventTimer;
+    bool m_override;
+    WebScreenOrientationType m_overrideType;
+    unsigned short m_overrideAngle;
 };
 
 } // namespace blink