Update from https://crrev.com/308331

net/test/embedded_test_server/embedded_test_server.cc

Index: net/test/embedded_test_server/embedded_test_server.cc
diff --git a/net/test/embedded_test_server/embedded_test_server.cc b/net/test/embedded_test_server/embedded_test_server.cc
index 97b5d84509c5f2324872ce69c3bfedf9459c582e..ac7d3bc14ac74f56b31f3ab83f5c7511f8cf6fb9 100644
--- a/net/test/embedded_test_server/embedded_test_server.cc
+++ b/net/test/embedded_test_server/embedded_test_server.cc
@@ -49,8 +49,15 @@ scoped_ptr<HttpResponse> HandleFileRequest(
   // This is a test-only server. Ignore I/O thread restrictions.
   base::ThreadRestrictions::ScopedAllowIO allow_io;
 
+  std::string relative_url(request.relative_url);
+  // A proxy request will have an absolute path. Simulate the proxy by stripping
+  // the scheme, host, and port.
+  GURL relative_gurl(relative_url);
+  if (relative_gurl.is_valid())
+    relative_url = relative_gurl.PathForRequest();
+
   // Trim the first byte ('/').
-  std::string request_path(request.relative_url.substr(1));
+  std::string request_path = relative_url.substr(1);
 
   // Remove the query string if present.
   size_t query_pos = request_path.find('?');