Merge the dart:uri library into dart:core and update the Uri class

runtime/vm/benchmark_test.cc

Index: runtime/vm/benchmark_test.cc
diff --git a/runtime/vm/benchmark_test.cc b/runtime/vm/benchmark_test.cc
index 2b19ef53f019d5266f48ada9ce28fda3d0b2b768..a85bc98450aa9b82d1c13f467fae9ed20d967795 100644
--- a/runtime/vm/benchmark_test.cc
+++ b/runtime/vm/benchmark_test.cc
@@ -434,7 +434,6 @@ BENCHMARK(StandaloneSnapshotSize) {
       "import 'dart:isolate';\n"
       "import 'dart:mirrors';\n"
       "import 'dart:typed_data';\n"
-      "import 'dart:uri';\n"
       "import 'dart:utf';\n"
       "import 'dart:json';\n"
       "import 'dart:crypto';\n"