Redraw media volume slider when it is moving

third_party/WebKit/Source/core/html/shadow/MediaControlElements.h

Index: third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
index df272a9493bee9dd77330ad7c5154beb82b50715..451f56e1dfca22fef842cac7356350ca6c3905dd 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.h
@@ -30,6 +30,7 @@
 #ifndef MediaControlElements_h
 #define MediaControlElements_h
 
+#include "core/CoreExport.h"
 #include "core/html/shadow/MediaControlElementTypes.h"
 #include "public/platform/WebLocalizedString.h"
 
@@ -352,7 +353,7 @@ class MediaControlVolumeSliderElement final : public MediaControlInputElement {
 
   bool willRespondToMouseMoveEvents() override;
   bool willRespondToMouseClickEvents() override;
-  void setVolume(double);
+  CORE_EXPORT void setVolume(double);
 
  private:
   explicit MediaControlVolumeSliderElement(MediaControls&);