Order function definitions in base/ according to the header.

base/crypto/symmetric_key_nss.cc

Index: base/crypto/symmetric_key_nss.cc
diff --git a/base/crypto/symmetric_key_nss.cc b/base/crypto/symmetric_key_nss.cc
index d291e8d3af77028e8b829aa78135a3ef2c38b1c4..1e3551d32ed75fc80132b1880b80facef44daad8 100644
--- a/base/crypto/symmetric_key_nss.cc
+++ b/base/crypto/symmetric_key_nss.cc
@@ -12,10 +12,6 @@
 
 namespace base {
 
-SymmetricKey::SymmetricKey(PK11SymKey* key) : key_(key) {
-  DCHECK(key);
-}
-
 SymmetricKey::~SymmetricKey() {}
 
 // static
@@ -124,4 +120,8 @@ bool SymmetricKey::GetRawKey(std::string* raw_key) {
   return true;
 }
 
+SymmetricKey::SymmetricKey(PK11SymKey* key) : key_(key) {
+  DCHECK(key);
+}
+
 }  // namespace base