Media Controls: move timeline related code to modules.

third_party/WebKit/Source/core/layout/LayoutSlider.h

Index: third_party/WebKit/Source/core/layout/LayoutSlider.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutSlider.h b/third_party/WebKit/Source/core/layout/LayoutSlider.h
index 3aceac2bef1af06d19719e509482e9199422081a..1815e2faa56ded817b16ea79a2b6c682c1578ac5 100644
--- a/third_party/WebKit/Source/core/layout/LayoutSlider.h
+++ b/third_party/WebKit/Source/core/layout/LayoutSlider.h
@@ -21,6 +21,7 @@
 #ifndef LayoutSlider_h
 #define LayoutSlider_h
 
+#include "core/CoreExport.h"
 #include "core/layout/LayoutFlexibleBox.h"
 
 namespace blink {
@@ -35,7 +36,7 @@ class LayoutSlider final : public LayoutFlexibleBox {
   explicit LayoutSlider(HTMLInputElement*);
   ~LayoutSlider() override;
 
-  bool InDragMode() const;
+  CORE_EXPORT bool InDragMode() const;
 
   const char* GetName() const override { return "LayoutSlider"; }