Expose APIs for text track settings

Source/web/WebSettingsImpl.h

Index: Source/web/WebSettingsImpl.h
diff --git a/Source/web/WebSettingsImpl.h b/Source/web/WebSettingsImpl.h
index ce8b35c84f787625e79cef8fcb4c21221683cf39..0b20bf77f2afa0a6059f7be5193cd3a52ed5bc0e 100644
--- a/Source/web/WebSettingsImpl.h
+++ b/Source/web/WebSettingsImpl.h
@@ -180,6 +180,14 @@ public:
     virtual void setWebSecurityEnabled(bool) override;
     virtual void setWideViewportQuirkEnabled(bool) override;
     virtual void setXSSAuditorEnabled(bool) override;
+    virtual void setTextTrackBackgroundColor(const WebString&);
+    virtual void setTextTrackFontFamily(const WebString&);
+    virtual void setTextTrackFontStyle(const WebString&);
+    virtual void setTextTrackFontVariant(const WebString&);
+    virtual void setTextTrackTextColor(const WebString&);
+    virtual void setTextTrackTextShadow(const WebString&);
+    virtual void setTextTrackTextSize(const WebString&);
+    virtual void setTextTrackWindowColor(const WebString&);
 
     bool showFPSCounter() const { return m_showFPSCounter; }
     bool showPaintRects() const { return m_showPaintRects; }