Make //crypto factories return std::unique_ptr<>s

crypto/symmetric_key.h

Index: crypto/symmetric_key.h
diff --git a/crypto/symmetric_key.h b/crypto/symmetric_key.h
index 2b2e2ce304fbb3c8f066cbf586663766ec063852..7494634b5ef5ad25693d87e82323234d6d05b853 100644
--- a/crypto/symmetric_key.h
+++ b/crypto/symmetric_key.h
@@ -7,6 +7,7 @@
 
 #include <stddef.h>
 
+#include <memory>
 #include <string>
 
 #include "base/macros.h"
@@ -31,25 +32,28 @@ class CRYPTO_EXPORT SymmetricKey {
   // Generates a random key suitable to be used with |algorithm| and of
   // |key_size_in_bits| bits. |key_size_in_bits| must be a multiple of 8.
   // The caller is responsible for deleting the returned SymmetricKey.
-  static SymmetricKey* GenerateRandomKey(Algorithm algorithm,
-                                         size_t key_size_in_bits);
+  static std::unique_ptr<SymmetricKey> GenerateRandomKey(
+      Algorithm algorithm,
+      size_t key_size_in_bits);
 
   // Derives a key from the supplied password and salt using PBKDF2, suitable
   // for use with specified |algorithm|. Note |algorithm| is not the algorithm
   // used to derive the key from the password. |key_size_in_bits| must be a
   // multiple of 8. The caller is responsible for deleting the returned
   // SymmetricKey.
-  static SymmetricKey* DeriveKeyFromPassword(Algorithm algorithm,
-                                             const std::string& password,
-                                             const std::string& salt,
-                                             size_t iterations,
-                                             size_t key_size_in_bits);
+  static std::unique_ptr<SymmetricKey> DeriveKeyFromPassword(
+      Algorithm algorithm,
+      const std::string& password,
+      const std::string& salt,
+      size_t iterations,
+      size_t key_size_in_bits);
 
   // Imports an array of key bytes in |raw_key|. This key may have been
   // generated by GenerateRandomKey or DeriveKeyFromPassword and exported with
   // GetRawKey, or via another compatible method. The key must be of suitable
   // size for use with |algorithm|. The caller owns the returned SymmetricKey.
-  static SymmetricKey* Import(Algorithm algorithm, const std::string& raw_key);
+  static std::unique_ptr<SymmetricKey> Import(Algorithm algorithm,
+                                              const std::string& raw_key);
 
   const std::string& key() { return key_; }
 
@@ -59,7 +63,8 @@ class CRYPTO_EXPORT SymmetricKey {
   bool GetRawKey(std::string* raw_key);
 
  private:
-  SymmetricKey() {}
+  SymmetricKey();
+
   std::string key_;
 
   DISALLOW_COPY_AND_ASSIGN(SymmetricKey);