Use Chromium BUILD to approximate Blimp protocol version, and check it.

blimp/common/version_info.cc.version

Index: blimp/common/version_info.cc.version
diff --git a/blimp/common/blob_cache/test_util.cc b/blimp/common/version_info.cc.version
similarity index 56%
copy from blimp/common/blob_cache/test_util.cc
copy to blimp/common/version_info.cc.version
index e416b815e61bc1b928a7da9cf6bd030108784233..9fb593ad2008ae05d37df5ba1e2766f5bdd9852e 100644
--- a/blimp/common/blob_cache/test_util.cc
+++ b/blimp/common/version_info.cc.version
@@ -2,12 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "blimp/common/blob_cache/test_util.h"
+#include "blimp/common/version_info.h"
 
 namespace blimp {
 
-BlobDataPtr CreateBlobDataPtr(const std::string& data) {
-  return new BlobData(data);
+int GetProtocolVersion() {
+  return @BUILD@;
+}
+
+std::string GetBuildVersion() {
+  return "@MAJOR@.@MINOR@.@BUILD@.@PATCH@";
 }
 
 }  // namespace blimp