Make code compile with clang_use_chrome_plugin (part I)

core/fpdfapi/fpdf_page/cpdf_pageobject.cpp

Index: core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
diff --git a/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp b/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
index ee6615e2e7ab4118f5abc9b13f80380f84c7634f..ebac18a596808a0aadac5a6a7c644e1da5a51e59 100644
--- a/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
@@ -10,6 +10,66 @@ CPDF_PageObject::CPDF_PageObject() {}
 
 CPDF_PageObject::~CPDF_PageObject() {}
 
+bool CPDF_PageObject::IsText() const {
+  return false;
+}
+
+bool CPDF_PageObject::IsPath() const {
+  return false;
+}
+
+bool CPDF_PageObject::IsImage() const {
+  return false;
+}
+
+bool CPDF_PageObject::IsShading() const {
+  return false;
+}
+
+bool CPDF_PageObject::IsForm() const {
+  return false;
+}
+
+CPDF_TextObject* CPDF_PageObject::AsText() {
+  return nullptr;
+}
+
+const CPDF_TextObject* CPDF_PageObject::AsText() const {
+  return nullptr;
+}
+
+CPDF_PathObject* CPDF_PageObject::AsPath() {
+  return nullptr;
+}
+
+const CPDF_PathObject* CPDF_PageObject::AsPath() const {
+  return nullptr;
+}
+
+CPDF_ImageObject* CPDF_PageObject::AsImage() {
+  return nullptr;
+}
+
+const CPDF_ImageObject* CPDF_PageObject::AsImage() const {
+  return nullptr;
+}
+
+CPDF_ShadingObject* CPDF_PageObject::AsShading() {
+  return nullptr;
+}
+
+const CPDF_ShadingObject* CPDF_PageObject::AsShading() const {
+  return nullptr;
+}
+
+CPDF_FormObject* CPDF_PageObject::AsForm() {
+  return nullptr;
+}
+
+const CPDF_FormObject* CPDF_PageObject::AsForm() const {
+  return nullptr;
+}
+
 void CPDF_PageObject::CopyData(const CPDF_PageObject* pSrc) {
   CopyStates(*pSrc);
   m_Left = pSrc->m_Left;