Make the TestServer use an absolute document root path.

net/test/local_test_server.cc

Index: net/test/local_test_server.cc
diff --git a/net/test/local_test_server.cc b/net/test/local_test_server.cc
index a24d6bb0d25a6ab975fe167c5c4c660b64b5f3da..95ffa064b32b242515ad8486e08311a34b0f7fc8 100644
--- a/net/test/local_test_server.cc
+++ b/net/test/local_test_server.cc
@@ -140,9 +140,6 @@ bool LocalTestServer::Stop() {
 }
 
 bool LocalTestServer::Init(const FilePath& document_root) {
-  if (document_root.IsAbsolute())
-    return false;
-
   // At this point, the port that the test server will listen on is unknown.
   // The test server will listen on an ephemeral port, and write the port
   // number out over a pipe that this TestServer object will read from. Once
@@ -153,7 +150,14 @@ bool LocalTestServer::Init(const FilePath& document_root) {
   FilePath src_dir;
   if (!PathService::Get(base::DIR_SOURCE_ROOT, &src_dir))
     return false;
-  SetResourcePath(src_dir.Append(document_root),
+
+  FilePath root;
+  if (document_root.IsAbsolute())
+    root = document_root;
+  else
+    root = src_dir.Append(document_root);
+
+  SetResourcePath(root,
                   src_dir.AppendASCII("net")
                          .AppendASCII("data")
                          .AppendASCII("ssl")