Eliminate unnecessary includes and pointless forward declarations in LayoutBlock.h

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003-2013 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ skipping 25 matching lines @@
 #ifndef LayoutBlockFlow_h
 #define LayoutBlockFlow_h
 
 #include "core/CoreExport.h"
 #include "core/layout/FloatingObjects.h"
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/api/LineLayoutItem.h"
 #include "core/layout/line/LineBoxList.h"
 #include "core/layout/line/RootInlineBox.h"
 #include "core/layout/line/TrailingObjects.h"
-#include "core/style/ComputedStyleConstants.h"
 
 namespace blink {
 
 class BlockChildrenLayoutInfo;
 class ClipScope;
 class MarginInfo;
 class LayoutInline;
-class LineBreaker;
 class LineInfo;
 class LineLayoutState;
 class LineWidth;
 class LayoutMultiColumnFlowThread;
 class LayoutMultiColumnSpannerPlaceholder;
 class LayoutRubyRun;
 template <class Run> class BidiRunList;
 
 enum IndentTextOrNot { DoNotIndentText, IndentText };
 
@@ skipping 606 matching lines @@
 
 // END METHODS DEFINED IN LayoutBlockFlowLine
 
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlockFlow, isLayoutBlockFlow());
 
 } // namespace blink
 
 #endif // LayoutBlockFlow_h