Add a ConvertableToTraceFormat type to the trace framework.

base/debug/trace_event_unittest.cc

 // Copyright (c) 2012 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_unittest.h"
 
 #include <cstdlib>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 1573 matching lines @@
   TRACE_EVENT_SAMPLE_STATE(1, "cc", "Things");
   sampled->Wait();
 
   EndTraceAndFlush();
 
   // Make sure we hit at least once.
   EXPECT_TRUE(FindNamePhase("Stuff", "P"));
   EXPECT_TRUE(FindNamePhase("Things", "P"));
 }
 
+class MyData : public base::debug::ConvertableToTraceFormat {
+ public:
+  MyData() {}
+  virtual ~MyData() {}
+
+  virtual void AppendAsTraceFormat(std::string* out) const OVERRIDE {
+    out->append("{\"foo\":1}");
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MyData);
+};
+
+TEST_F(TraceEventTestFixture, ConvertableTypes) {
+  ManualTestSetUp();
+  TraceLog::GetInstance()->SetEnabled(true, TraceLog::RECORD_UNTIL_FULL);
+
+  scoped_ptr<MyData> data(new MyData());
+  TRACE_EVENT1("foo", "bar", "data",
+               data.PassAs<base::debug::ConvertableToTraceFormat>());
+  EndTraceAndFlush();
+
+  DictionaryValue* dict = FindNamePhase("bar", "B");
+  ASSERT_TRUE(dict);
+
+  const DictionaryValue* args_dict = NULL;
+  dict->GetDictionary("args", &args_dict);
+  ASSERT_TRUE(args_dict);
+
+  const Value* value = NULL;
+  const DictionaryValue* convertable_dict = NULL;
+  EXPECT_TRUE(args_dict->Get("data", &value));
+  ASSERT_TRUE(value->GetAsDictionary(&convertable_dict));
+
+  int foo_val;
+  EXPECT_TRUE(convertable_dict->GetInteger("foo", &foo_val));
+  EXPECT_EQ(1, foo_val);
+}
+
+
 class TraceEventCallbackTest : public TraceEventTestFixture {
  public:
   virtual void SetUp() OVERRIDE {
     TraceEventTestFixture::SetUp();
     ManualTestSetUp();
     ASSERT_EQ(NULL, s_instance);
     s_instance = this;
   }
   virtual void TearDown() OVERRIDE {
     while (TraceLog::GetInstance()->IsEnabled())
@@ skipping 34 matching lines @@
                        TRACE_EVENT_SCOPE_GLOBAL);
   EXPECT_EQ(2u, collected_events_.size());
   EXPECT_EQ("event1", collected_events_[0]);
   EXPECT_EQ("event2", collected_events_[1]);
 }
 
 // TODO(dsinclair): Continuous Tracing unit test.
 
 }  // namespace debug
 }  // namespace base