Clean up some API in trace_event_analyzer.h and add some getters.

base/test/trace_event_analyzer_unittest.cc

Index: base/test/trace_event_analyzer_unittest.cc
diff --git a/base/test/trace_event_analyzer_unittest.cc b/base/test/trace_event_analyzer_unittest.cc
index 2047b120b83f084345c648f8a577a2ec0b6a0605..fe18ffb4b8fc60b1e506c030257e9a073ee0ce33 100644
--- a/base/test/trace_event_analyzer_unittest.cc
+++ b/base/test/trace_event_analyzer_unittest.cc
@@ -96,8 +96,8 @@ TEST_F(TraceEventAnalyzerTest, QueryEventMember) {
   other.arg_strings["str2"] = "the string 2";
 
   event.other_event = &other;
-  double duration;
-  ASSERT_TRUE(event.GetAbsTimeToOtherEvent(&duration));
+  ASSERT_TRUE(event.has_other_event());
+  double duration = event.GetAbsTimeToOtherEvent();
 
   Query event_pid = (Query(EVENT_PID) == Query::Int(event.thread.process_id));
   Query event_tid = (Query(EVENT_TID) == Query::Int(event.thread.thread_id));
@@ -107,8 +107,8 @@ TEST_F(TraceEventAnalyzerTest, QueryEventMember) {
   Query event_category =
       (Query(EVENT_CATEGORY) == Query::String(event.category));
   Query event_name = (Query(EVENT_NAME) == Query::String(event.name));
-  Query event_has_arg1 = Query(EVENT_HAS_ARG, "num");
-  Query event_has_arg2 = Query(EVENT_HAS_ARG, "str");
+  Query event_has_arg1 = Query(EVENT_HAS_NUMBER_ARG, "num");
+  Query event_has_arg2 = Query(EVENT_HAS_STRING_ARG, "str");
   Query event_arg1 =
       (Query(EVENT_ARG, "num") == Query::Double(event.arg_numbers["num"]));
   Query event_arg2 =
@@ -121,8 +121,8 @@ TEST_F(TraceEventAnalyzerTest, QueryEventMember) {
   Query other_category =
       (Query(OTHER_CATEGORY) == Query::String(other.category));
   Query other_name = (Query(OTHER_NAME) == Query::String(other.name));
-  Query other_has_arg1 = Query(OTHER_HAS_ARG, "num2");
-  Query other_has_arg2 = Query(OTHER_HAS_ARG, "str2");
+  Query other_has_arg1 = Query(OTHER_HAS_NUMBER_ARG, "num2");
+  Query other_has_arg2 = Query(OTHER_HAS_STRING_ARG, "str2");
   Query other_arg1 =
       (Query(OTHER_ARG, "num2") == Query::Double(other.arg_numbers["num2"]));
   Query other_arg2 =