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, 4 insertions, 5 deletions

diff --git a/core/fpdfapi/fpdf_page/cpdf_contentmarkdata.h b/core/fpdfapi/fpdf_page/cpdf_contentmarkdata.h
index 773fea741b..6f5c1f1fae 100644
--- a/core/fpdfapi/fpdf_page/cpdf_contentmarkdata.h
+++ b/core/fpdfapi/fpdf_page/cpdf_contentmarkdata.h
@@ -16,14 +16,13 @@ class CPDF_Dictionary;
 
 class CPDF_ContentMarkData {
  public:
-  CPDF_ContentMarkData() {}
+  CPDF_ContentMarkData();
   CPDF_ContentMarkData(const CPDF_ContentMarkData& src);
+  ~CPDF_ContentMarkData();
 
   int CountItems() const;
-  CPDF_ContentMarkItem& GetItem(int index) { return m_Marks[index]; }
-  const CPDF_ContentMarkItem& GetItem(int index) const {
-    return m_Marks[index];
-  }
+  CPDF_ContentMarkItem& GetItem(int index);
+  const CPDF_ContentMarkItem& GetItem(int index) const;
 
   int GetMCID() const;
   void AddMark(const CFX_ByteString& name,