Rename CFX_RetainPtr to RetainPtr

This CL renames CFX_RetainPtr to RetainPtr and places in the fxcrt
namespace.

Bug: pdfium:898
Change-Id: I8798a9f79cb0840d3f037e8d04937cedd742914e
Reviewed-on: https://pdfium-review.googlesource.com/14616
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
diff --git a/core/fpdfapi/render/cpdf_type3cache.h b/core/fpdfapi/render/cpdf_type3cache.h
index ab748ba..fe681bb 100644
--- a/core/fpdfapi/render/cpdf_type3cache.h
+++ b/core/fpdfapi/render/cpdf_type3cache.h
@@ -11,17 +11,17 @@
 #include <memory>
 
 #include "core/fpdfapi/font/cpdf_type3font.h"
-#include "core/fxcrt/cfx_retain_ptr.h"
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
+#include "core/fxcrt/retain_ptr.h"
 
 class CPDF_Type3Glyphs;
 
-class CPDF_Type3Cache : public CFX_Retainable {
+class CPDF_Type3Cache : public Retainable {
  public:
   template <typename T, typename... Args>
-  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
+  friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   CFX_GlyphBitmap* LoadGlyph(uint32_t charcode,
                              const CFX_Matrix* pMatrix,