LatencyInfo trace_id_ no longer dependent on sequence_number.

ui/latency/mojo/struct_traits_unittest.cc

Index: ui/latency/mojo/struct_traits_unittest.cc
diff --git a/ui/latency/mojo/struct_traits_unittest.cc b/ui/latency/mojo/struct_traits_unittest.cc
index 7e78399de6346ecd80d28c87e638aba0fa546f06..2dbcc3a246d78d3b668724b92c08cd0b642d5205 100644
--- a/ui/latency/mojo/struct_traits_unittest.cc
+++ b/ui/latency/mojo/struct_traits_unittest.cc
@@ -80,13 +80,14 @@ TEST_F(StructTraitsTest, LatencyComponentId) {
 
 TEST_F(StructTraitsTest, LatencyInfo) {
   LatencyInfo latency;
+  latency.set_trace_id(5);
   ASSERT_FALSE(latency.terminated());
   latency.AddLatencyNumber(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT, 1234, 0);
   latency.AddLatencyNumber(INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT, 1234, 100);
   latency.AddLatencyNumber(INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT,
                            1234, 0);
 
-  EXPECT_EQ(100, latency.trace_id());
+  EXPECT_EQ(5, latency.trace_id());
   EXPECT_TRUE(latency.terminated());
 
   latency.set_source_event_type(ui::TOUCH);