Refactor FileVersionInfo into an interface with platform implementations.

webkit/tools/test_shell/test_shell.cc

Index: webkit/tools/test_shell/test_shell.cc
diff --git a/webkit/tools/test_shell/test_shell.cc b/webkit/tools/test_shell/test_shell.cc
index ba3a2c2b69c8bd0dcacdcad9bfbc60c66e8077b8..d529ba7aa4faa8bc9c9cf0c8f345c53e62758268 100644
--- a/webkit/tools/test_shell/test_shell.cc
+++ b/webkit/tools/test_shell/test_shell.cc
@@ -801,4 +801,8 @@ void SetCacheMode(bool enabled) {
   // Used in benchmarking,  Ignored for test_shell.
 }
 
+std::string GetProductVersion() {
+  return std::string("Chrome/0.0.0.0");
+}
+
 }  // namespace webkit_glue