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 78b3ed75c0c5bfa261c4db8b43dd5f4cc2088314..ebcd320e12b9bcc66159a5977360d249334d6d1c 100644
--- a/Source/web/WebSettingsImpl.h
+++ b/Source/web/WebSettingsImpl.h
@@ -161,6 +161,13 @@ public:
     virtual void setTextAreasAreResizable(bool) override;
     virtual void setTextAutosizingEnabled(bool) override;
     virtual void setAccessibilityFontScaleFactor(float) 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 setThreadedScrollingEnabled(bool) override;
     virtual void setTouchDragDropEnabled(bool) override;
     virtual void setTouchEditingEnabled(bool) override;