QFontEngine: remove unused and buggy grayPalette()

QFontEngine::grayPalette() mistakenly returns an
empty vector, so even if there's a user (the class
it exported, after all), it cannot correctly use it.

So, just remove it.

Change-Id: Id5f70139e5f6ed9a2a3f28400cd0750d14cb7dc0
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Jiang Jiang <jiang.jiang@nokia.com>

src/gui/text/qfontengine.cpp

@@ -1148,25 +1148,6 @@ QByteArray QFontEngine::convertToPostscriptFontFamilyName(const QByteArray &fami
     return f;
 }
 
-class QRgbGreyPalette: public QVector<QRgb>
-{
-public:
-    QRgbGreyPalette()
-    {
-        resize(256);
-        QRgb *it = data();
-        for (int i = 0; i < size(); ++i, ++it)
-            *it = 0xff000000 | i | (i<<8) | (i<<16);
-    }
-};
-
-Q_GLOBAL_STATIC(QVector<QRgb>, qt_grayPalette)
-
-const QVector<QRgb> &QFontEngine::grayPalette()
-{
-    return *qt_grayPalette();
-}
-
 QFixed QFontEngine::lastRightBearing(const QGlyphLayout &glyphs, bool round)
 {
     if (glyphs.numGlyphs >= 1) {

src/gui/text/qfontengine_p.h

@@ -278,7 +278,6 @@ public:
     int m_subPixelPositionCount; // Number of positions within a single pixel for this cache
 
 protected:
-    static const QVector<QRgb> &grayPalette();
     QFixed lastRightBearing(const QGlyphLayout &glyphs, bool round = false);
 
 private: