Make the TestServer use an absolute document root path.

net/test/local_test_server.h

Index: net/test/local_test_server.h
diff --git a/net/test/local_test_server.h b/net/test/local_test_server.h
index fcc7ebf5135ad0265dcedbf784f917a0644434d5..3474e1e433444bb714e03d08a26b742a60364d98 100644
--- a/net/test/local_test_server.h
+++ b/net/test/local_test_server.h
@@ -24,13 +24,13 @@ namespace net {
 class LocalTestServer : public BaseTestServer {
  public:
   // Initialize a TestServer listening on a specific host (IP or hostname).
-  // |document_root| must be a relative path under the root tree.
+  // |document_root| must be an absolute path.
   LocalTestServer(Type type,
                   const std::string& host,
                   const base::FilePath& document_root);
 
   // Initialize a TestServer with a specific set of SSLOptions.
-  // |document_root| must be a relative path under the root tree.
+  // |document_root| must be an absolute path.
   LocalTestServer(Type type,
                   const SSLOptions& ssl_options,
                   const base::FilePath& document_root);