Make code compile with clang_use_chrome_plugin (part I)

This change contains files in core/fpdfapi directory. This is part
of the efforts to make PDFium code compilable by Clang chromium
style plugins.

The changes are mainly the following:
-- move inline constructor/destructor of complex class/struct out-of-line;
-- add constructor/destructor of complex class/struct if not
   explicitly defined;
-- add explicit out-of-line copy constructor when needed;
-- move inline virtual functions out-of-line;
-- Properly mark virtual functions with 'override';
-- some minor cleanups;

BUG=pdfium:469

Review-Url: https://codereview.chromium.org/2060973002

1 files changed, 5 insertions, 5 deletions

diff --git a/core/fpdfapi/fpdf_page/include/cpdf_shadingobject.h b/core/fpdfapi/fpdf_page/include/cpdf_shadingobject.h
index ae2ee90083..0607bcb42c 100644
--- a/core/fpdfapi/fpdf_page/include/cpdf_shadingobject.h
+++ b/core/fpdfapi/fpdf_page/include/cpdf_shadingobject.h
@@ -17,13 +17,13 @@ class CPDF_ShadingObject : public CPDF_PageObject {
   CPDF_ShadingObject();
   ~CPDF_ShadingObject() override;
 
-  // CPDF_PageObject:
+  // CPDF_PageObject
   CPDF_ShadingObject* Clone() const override;
-  Type GetType() const override { return SHADING; };
+  Type GetType() const override;
   void Transform(const CFX_Matrix& matrix) override;
-  bool IsShading() const override { return true; };
-  CPDF_ShadingObject* AsShading() override { return this; };
-  const CPDF_ShadingObject* AsShading() const override { return this; };
+  bool IsShading() const override;
+  CPDF_ShadingObject* AsShading() override;
+  const CPDF_ShadingObject* AsShading() const override;
 
   void CalcBoundingBox();