Some small cleanups to Lock suggested by Gaetano Mendola.
Review URL: http://codereview.chromium.org/6037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@2754 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: b4fef872bdb00afec096a716cfe05f2c3d600850
diff --git a/base/lock.h b/base/lock.h
index ee22fa6..4e736af 100644
--- a/base/lock.h
+++ b/base/lock.h
@@ -55,7 +55,7 @@
 // A helper class that acquires the given Lock while the AutoLock is in scope.
 class AutoLock {
  public:
-  AutoLock(Lock& lock) : lock_(lock) {
+  explicit AutoLock(Lock& lock) : lock_(lock) {
     lock_.Acquire();
   }