Add defaulted move constructors for some types that just got copy constructors

webrtc/base/pathutils.h

Index: webrtc/base/pathutils.h
diff --git a/webrtc/base/pathutils.h b/webrtc/base/pathutils.h
index c155e8cd1dc20281f6d547c274c4e18b9c559b32..2a0efa9763f8a0604482ae2556243b5de23b55d4 100644
--- a/webrtc/base/pathutils.h
+++ b/webrtc/base/pathutils.h
@@ -45,9 +45,13 @@ public:
 
   Pathname();
   Pathname(const Pathname&);
+  Pathname(Pathname&&);
   Pathname(const std::string& pathname);
   Pathname(const std::string& folder, const std::string& filename);
 
+  Pathname& operator=(const Pathname&);
+  Pathname& operator=(Pathname&&);
+
   // Set's the default folder delimiter for this Pathname
   char folder_delimiter() const { return folder_delimiter_; }
   void SetFolderDelimiter(char delimiter);