Add builders for tracing event's structural arguments

base/debug/trace_event_argument_unittest.cc

Index: base/debug/trace_event_argument_unittest.cc
diff --git a/base/debug/trace_event_argument_unittest.cc b/base/debug/trace_event_argument_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..06a7697f0828f2099844d96813e6cfa31d14c224
--- /dev/null
+++ b/base/debug/trace_event_argument_unittest.cc
@@ -0,0 +1,53 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/debug/trace_event_argument.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace debug {
+
+TEST(TraceEventArgumentTest, FlatDictionary) {
+  scoped_refptr<TracedValue> value = new TracedValue();
+  value->SetInteger("int", 2014);
+  value->SetDouble("double", 0.0);
+  value->SetBoolean("bool", true);
+  value->SetString("string", "string");
+  std::string json;
+  value->AppendAsTraceFormat(&json);
+  EXPECT_EQ("{\"bool\":true,\"double\":0.0,\"int\":2014,\"string\":\"string\"}",
+            json);
+}
+
+TEST(TraceEventArgumentTest, Hierarchy) {
+  scoped_refptr<TracedValue> value = new TracedValue();
+  value->SetInteger("i0", 2014);
+  value->BeginDictionary("dict1");
+  value->SetInteger("i1", 2014);
+  value->BeginDictionary("dict2");
+  value->SetBoolean("b2", false);
+  value->EndDictionary();
+  value->SetString("s1", "foo");
+  value->EndDictionary();
+  value->SetDouble("d0", 0.0);
+  value->SetBoolean("b0", true);
+  value->BeginArray("a1");
+  value->AppendInteger(1);
+  value->AppendBoolean(true);
+  value->BeginDictionary();
+  value->SetInteger("i2", 3);
+  value->EndDictionary();
+  value->EndArray();
+  value->SetString("s0", "foo");
+  std::string json;
+  value->AppendAsTraceFormat(&json);
+  EXPECT_EQ(
+      "{\"a1\":[1,true,{\"i2\":3}],\"b0\":true,\"d0\":0.0,\"dict1\":{\"dict2\":"
+      "{\"b2\":false},\"i1\":2014,\"s1\":\"foo\"},\"i0\":2014,\"s0\":"
+      "\"foo\"}",
+      json);
+}
+
+}  // namespace debug
+}  // namespace base