Remove include only fwl.h and IWYU.

xfa/include/fwl/core/fwl_theme.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef XFA_INCLUDE_FWL_CORE_FWL_THEME_H_
 #define XFA_INCLUDE_FWL_CORE_FWL_THEME_H_
 
+#include "xfa/include/fwl/core/fwl_error.h"
+#include "xfa/include/fxgraphics/fx_graphics.h"
+
 class IFWL_Widget;
-class CFWL_ThemePart;
-class CFWL_ThemeBackground;
-class CFWL_ThemeText;
-class CFWL_ThemeElement;
-class IFWL_ThemeProvider;
+
 #define FWL_WGTCAPACITY_CXBorder 1
 #define FWL_WGTCAPACITY_CYBorder 2
 #define FWL_WGTCAPACITY_ScrollBarWidth 3
 #define FWL_WGTCAPACITY_EdgeFlat 4
 #define FWL_WGTCAPACITY_EdgeRaised 5
 #define FWL_WGTCAPACITY_EdgeSunken 6
 #define FWL_WGTCAPACITY_Font 7
 #define FWL_WGTCAPACITY_FontSize 8
 #define FWL_WGTCAPACITY_TextColor 9
 #define FWL_WGTCAPACITY_TextSelColor 10
 #define FWL_WGTCAPACITY_LineHeight 11
 #define FWL_WGTCAPACITY_UIMargin 12
 #define FWL_WGTCAPACITY_SpaceAboveBelow 13
 #define FWL_WGTCAPACITY_MAX 65535
+
 class CFWL_ThemePart {
  public:
   CFWL_ThemePart()
       : m_pWidget(NULL), m_iPart(0), m_dwStates(0), m_dwData(0), m_pData(NULL) {
     m_rtPart.Reset();
     m_matrix.SetIdentity();
   }
   CFX_Matrix m_matrix;
   CFX_RectF m_rtPart;
   IFWL_Widget* m_pWidget;
@@ skipping 35 matching lines @@
   virtual FX_BOOL IsCustomizedLayout(IFWL_Widget* pWidget) = 0;
   virtual FWL_ERR GetPartRect(CFWL_ThemePart* pThemePart,
                               CFX_RectF& rtPart) = 0;
   virtual FX_BOOL IsInPart(CFWL_ThemePart* pThemePart,
                            FX_FLOAT fx,
                            FX_FLOAT fy) = 0;
   virtual FX_BOOL CalcTextRect(CFWL_ThemeText* pParams, CFX_RectF& rect) = 0;
 };
 
 #endif  // XFA_INCLUDE_FWL_CORE_FWL_THEME_H_