trace event patch

local changes.patch

diff --git a/base/trace_event/common/trace_event_common.h b/base/trace_event/common/trace_event_common.h
index f2ee4d36b317d..7d5731053bbd7 100644
--- a/base/trace_event/common/trace_event_common.h
+++ b/base/trace_event/common/trace_event_common.h
@@ -965,6 +965,13 @@ struct BASE_EXPORT TraceTimestampTraits<::base::TimeTicks> {
       TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, category_group, name, id,    \
       TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_COPY, \
       arg1_name, arg1_val)
+#define TRACE_EVENT_COPY_NESTABLE_ASYNC_BEGIN_WITH_TIMESTAMP2(             \
+    category_group, name, id, timestamp, arg1_name, arg1_val,              \
+    arg2_name, arg2_val)                                                   \
+  INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                      \
+      TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, category_group, name, id,    \
+      TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_COPY, \
+      arg1_name, arg1_val, arg2_name, arg2_val)
 #define TRACE_EVENT_COPY_NESTABLE_ASYNC_END_WITH_TIMESTAMP0(          \
     category_group, name, id, timestamp)                              \
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                 \
diff --git a/third_party/blink/renderer/core/timing/performance_user_timing.cc b/third_party/blink/renderer/core/timing/performance_user_timing.cc
index 1056e5c6f04d7..0ee17e6c6efc2 100644
--- a/third_party/blink/renderer/core/timing/performance_user_timing.cc
+++ b/third_party/blink/renderer/core/timing/performance_user_timing.cc
@@ -36,6 +36,7 @@
 #include "third_party/blink/renderer/platform/bindings/exception_state.h"
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_hash.h"
+#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
 
 namespace blink {
 
@@ -209,10 +210,12 @@ PerformanceMeasure* UserTiming::Measure(ScriptState* script_state,
     unsigned hash = WTF::GetHash(measure_name);
     WTF::AddFloatToHash(hash, start_time);
     WTF::AddFloatToHash(hash, end_time);
+    WTF::String serialized_detail;
+    detail.ToString(serialized_detail);
 
-    TRACE_EVENT_COPY_NESTABLE_ASYNC_BEGIN_WITH_TIMESTAMP1(
+    TRACE_EVENT_COPY_NESTABLE_ASYNC_BEGIN_WITH_TIMESTAMP2(
         "blink.user_timing", measure_name.Utf8().c_str(), hash,
-        unsafe_start_time, "startTime", start_time);
+        unsafe_start_time, "startTime", start_time, "detail", serialized_detail);
     TRACE_EVENT_COPY_NESTABLE_ASYNC_END_WITH_TIMESTAMP0(
         "blink.user_timing", measure_name.Utf8().c_str(), hash,
         unsafe_end_time);
diff --git a/third_party/blink/web_tests/inspector-protocol/timeline/user-timing-expected.txt b/third_party/blink/web_tests/inspector-protocol/timeline/user-timing-expected.txt
index 022ce7fb3734a..7b33b661db1b0 100644
--- a/third_party/blink/web_tests/inspector-protocol/timeline/user-timing-expected.txt
+++ b/third_party/blink/web_tests/inspector-protocol/timeline/user-timing-expected.txt
@@ -2,13 +2,23 @@ Tests render blocking status in script traces.
 Recording started
 Tracing complete
 now to first
+undefined
 now
+undefined
 now to first
+undefined
 first to second
+undefined
 first to third
+undefined
 first
+undefined
 first to second
+undefined
 second
+undefined
 first to third
+undefined
 third
+undefined
 
diff --git a/third_party/blink/web_tests/inspector-protocol/timeline/user-timing.js b/third_party/blink/web_tests/inspector-protocol/timeline/user-timing.js
index cbb8fc54cbc55..cf0316b44b47f 100644
--- a/third_party/blink/web_tests/inspector-protocol/timeline/user-timing.js
+++ b/third_party/blink/web_tests/inspector-protocol/timeline/user-timing.js
@@ -34,6 +34,7 @@
 
   for (let e of sorted_events) {
     testRunner.log(e["name"]);
+    testRunner.log(e["detail"]);
   }
 
   testRunner.completeTest();