Remove uses of gfe2::test::GenerateBody from QUIC code and use the string fill constructor instead.

net/tools/quic/quic_simple_server_session_test.cc

Index: net/tools/quic/quic_simple_server_session_test.cc
diff --git a/net/tools/quic/quic_simple_server_session_test.cc b/net/tools/quic/quic_simple_server_session_test.cc
index 13409e47e8f0a5240da188b36d8f69c3a5a1911c..7a9e1e4e22ac7d5b1c6ff4d9483e49d4e039d604 100644
--- a/net/tools/quic/quic_simple_server_session_test.cc
+++ b/net/tools/quic/quic_simple_server_session_test.cc
@@ -476,8 +476,7 @@ class QuicSimpleServerSessionServerPushTest
       string path = partial_push_resource_path + base::UintToString(i);
       string url = scheme + "://" + resource_host + path;
       GURL resource_url = GURL(url);
-      string body;
-      GenerateBody(&body, body_size);
+      string body(body_size, 'a');
       in_memory_cache_.AddSimpleResponse(resource_host, path, 200, body);
       push_resources.push_back(QuicInMemoryCache::ServerPushInfo(
           resource_url, SpdyHeaderBlock(), kDefaultPriority, body));