Make the TestServer use an absolute document root path.

net/test/remote_test_server.cc

Index: net/test/remote_test_server.cc
diff --git a/net/test/remote_test_server.cc b/net/test/remote_test_server.cc
index 3421fa55ebecd27cac35f6b07a85022624f92e1a..f806195f895af34499e81401140b423719afc7c0 100644
--- a/net/test/remote_test_server.cc
+++ b/net/test/remote_test_server.cc
@@ -161,9 +161,6 @@ FilePath RemoteTestServer::GetDocumentRoot() const {
 }
 
 bool RemoteTestServer::Init(const FilePath& document_root) {
-  if (document_root.IsAbsolute())
-    return false;
-
   // Gets ports information used by test server spawner and Python test server.
   int test_server_port = 0;
 
@@ -193,10 +190,20 @@ bool RemoteTestServer::Init(const FilePath& document_root) {
     return false;
   SetPort(test_server_port);
 
-  SetResourcePath(document_root, FilePath().AppendASCII("net")
-                                           .AppendASCII("data")
-                                           .AppendASCII("ssl")
-                                           .AppendASCII("certificates"));
+  FilePath root;
+  if (document_root.IsAbsolute()) {
+    root = document_root;
+  } else {
+    FilePath src_dir;
+    if (!PathService::Get(base::DIR_SOURCE_ROOT, &src_dir))
+      return false;
+    root = src_dir.Append(document_root);
+  }
+
+  SetResourcePath(root, FilePath().AppendASCII("net")
+                                  .AppendASCII("data")
+                                  .AppendASCII("ssl")
+                                  .AppendASCII("certificates"));
   return true;
 }