Remove dead code backing WheelEvent.webkitDirectionInvertedFromDevice

Source/platform/PlatformWheelEvent.h

Index: Source/platform/PlatformWheelEvent.h
diff --git a/Source/platform/PlatformWheelEvent.h b/Source/platform/PlatformWheelEvent.h
index d4c4bad9e80623ad1fdfd9f2e733879ebb0b2c5f..588013c68552aa4e5edb389d66ce7d6c141a2ddf 100644
--- a/Source/platform/PlatformWheelEvent.h
+++ b/Source/platform/PlatformWheelEvent.h
@@ -65,7 +65,6 @@ public:
         , m_wheelTicksX(0)
         , m_wheelTicksY(0)
         , m_granularity(ScrollByPixelWheelEvent)
-        , m_directionInvertedFromDevice(false)
         , m_hasPreciseScrollingDeltas(false)
 #if OS(MACOSX)
         , m_phase(PlatformWheelEventPhaseNone)
@@ -88,7 +87,6 @@ public:
         , m_wheelTicksX(wheelTicksX)
         , m_wheelTicksY(wheelTicksY)
         , m_granularity(granularity)
-        , m_directionInvertedFromDevice(false)
         , m_hasPreciseScrollingDeltas(false)
 #if OS(MACOSX)
         , m_phase(PlatformWheelEventPhaseNone)
@@ -113,8 +111,6 @@ public:
 
     PlatformWheelEventGranularity granularity() const { return m_granularity; }
 
-    bool directionInvertedFromDevice() const { return m_directionInvertedFromDevice; }
-
     bool hasPreciseScrollingDeltas() const { return m_hasPreciseScrollingDeltas; }
     void setHasPreciseScrollingDeltas(bool b) { m_hasPreciseScrollingDeltas = b; }
 #if OS(MACOSX)
@@ -138,7 +134,6 @@ protected:
     float m_wheelTicksX;
     float m_wheelTicksY;
     PlatformWheelEventGranularity m_granularity;
-    bool m_directionInvertedFromDevice;
     bool m_hasPreciseScrollingDeltas;
 #if OS(MACOSX)
     PlatformWheelEventPhase m_phase;