Make code compile with clang_use_chrome_plugin (part I)

core/fpdfapi/fpdf_page/cpdf_shadingobject.cpp

 // Copyright 2016 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
 
 #include "core/fpdfapi/fpdf_page/include/cpdf_shadingobject.h"
 
 #include "core/fpdfapi/fpdf_page/cpdf_shadingpattern.h"
 #include "core/fpdfapi/fpdf_page/pageint.h"
@@ skipping 12 matching lines @@
     CPDF_DocPageData* pDocPageData = obj->m_pShading->document()->GetPageData();
     CPDF_Pattern* pattern = pDocPageData->GetPattern(
         obj->m_pShading->GetShadingObject(), m_pShading->IsShadingObject(),
         obj->m_pShading->parent_matrix());
     obj->m_pShading = pattern ? pattern->AsShadingPattern() : nullptr;
   }
   obj->m_Matrix = m_Matrix;
   return obj;
 }
 
+CPDF_PageObject::Type CPDF_ShadingObject::GetType() const {
+  return SHADING;
+}
+
 void CPDF_ShadingObject::Transform(const CFX_Matrix& matrix) {
   if (!m_ClipPath.IsNull()) {
     m_ClipPath.GetModify();
     m_ClipPath.Transform(matrix);
   }
   m_Matrix.Concat(matrix);
   if (!m_ClipPath.IsNull()) {
     CalcBoundingBox();
   } else {
     matrix.TransformRect(m_Left, m_Right, m_Top, m_Bottom);
   }
 }
 
+bool CPDF_ShadingObject::IsShading() const {
+  return true;
+}
+
+CPDF_ShadingObject* CPDF_ShadingObject::AsShading() {
+  return this;
+}
+
+const CPDF_ShadingObject* CPDF_ShadingObject::AsShading() const {
+  return this;
+}
+
 void CPDF_ShadingObject::CalcBoundingBox() {
   if (m_ClipPath.IsNull()) {
     return;
   }
   CFX_FloatRect rect = m_ClipPath.GetClipBox();
   m_Left = rect.left;
   m_Bottom = rect.bottom;
   m_Right = rect.right;
   m_Top = rect.top;
 }