Clean up forward declarations in Source/core/page

Source/core/page/scrolling/ScrollingCoordinator.h

Index: Source/core/page/scrolling/ScrollingCoordinator.h
diff --git a/Source/core/page/scrolling/ScrollingCoordinator.h b/Source/core/page/scrolling/ScrollingCoordinator.h
index 93b25707392d9bbf25752b617e60806f5cda2494..68cce85294fd320a19551399545f8167530fefa4 100644
--- a/Source/core/page/scrolling/ScrollingCoordinator.h
+++ b/Source/core/page/scrolling/ScrollingCoordinator.h
@@ -33,7 +33,6 @@
 #include "wtf/text/WTFString.h"
 
 namespace blink {
-class WebLayer;
 class WebScrollbarLayer;
 }
 
@@ -41,14 +40,12 @@ namespace blink {
 
 typedef unsigned MainThreadScrollingReasons;
 
-class Document;
 class LocalFrame;
 class FrameView;
 class GraphicsLayer;
 class Page;
 class Region;
 class ScrollableArea;
-class ViewportConstraints;
 
 class ScrollingCoordinator {
 public: