Fix external snapshot compilation

TBR=yangguo@chromium.org
LOG=n
BUG=none

Review URL: https://codereview.chromium.org/341433005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22097 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/snapshot-external.cc

@@ -50,7 +50,7 @@ bool Snapshot::Initialize() {
   if (!HaveASnapshotToStartFrom())
     return false;
 
-  ElapsedTimer timer;
+  base::ElapsedTimer timer;
   if (FLAG_profile_deserialization) {
     timer.Start();
   }