Catch stray Retains() and Releases() outside of RetainPtr<>.

core/fxcrt/cfx_retain_ptr_unittest.cpp

Index: core/fxcrt/cfx_retain_ptr_unittest.cpp
diff --git a/core/fxcrt/cfx_retain_ptr_unittest.cpp b/core/fxcrt/cfx_retain_ptr_unittest.cpp
index 692beb82ffdf3eadd21d408007a2617ea31a5d85..1389cd802b0fe26cbd47c6b7cff65aa8364be542 100644
--- a/core/fxcrt/cfx_retain_ptr_unittest.cpp
+++ b/core/fxcrt/cfx_retain_ptr_unittest.cpp
@@ -14,12 +14,18 @@ namespace {
 class PseudoRetainable {
  public:
   PseudoRetainable() : retain_count_(0), release_count_(0) {}
-  void Retain() { ++retain_count_; }
-  void Release() { ++release_count_; }
   int retain_count() const { return retain_count_; }
   int release_count() const { return release_count_; }
 
  private:
+  template <typename U>
+  friend struct ::ReleaseDeleter;
+  template <typename U>
+  friend class ::CFX_RetainPtr;
+
+  void Retain() { ++retain_count_; }
+  void Release() { ++release_count_; }
+
   int retain_count_;
   int release_count_;
 };