about:gpu support for thread name metadata.

chrome/browser/resources/gpu_internals/tracing_controller_tests.js

Index: chrome/browser/resources/gpu_internals/tracing_controller_tests.js
diff --git a/chrome/browser/resources/gpu_internals/tracing_controller_tests.js b/chrome/browser/resources/gpu_internals/tracing_controller_tests.js
index b4ad5d2371850cd56c71939f800713ed0de71cdf..53c979d45a7626aab7cfd0b7085d64b6d85e5486 100644
--- a/chrome/browser/resources/gpu_internals/tracing_controller_tests.js
+++ b/chrome/browser/resources/gpu_internals/tracing_controller_tests.js
@@ -8,6 +8,15 @@ cr.define('gpu', function() {
       events_url: "./tests/big_trace.json"
     },
     {
+      name: "trivial_trace",
+      events: [
+        {"name":"a","args":{},"pid":6052,"ts":3074899524,"cat":"foo","tid":6053,"ph":"B"},
+        {"name":"a","args":{},"pid":6052,"ts":3074899560,"cat":"foo","tid":6053,"ph":"E"},
+        {"name":"b","args":{},"pid":6052,"ts":3074899629,"cat":"foo","tid":6053,"ph":"B"},
+        {"name":"b","args":{},"pid":6052,"ts":3074899631,"cat":"foo","tid":6053,"ph":"E"},
+      ]
+    },
+    {
       name: "simple_trace",
       events: [
         {"cat":"PERF","pid":22630,"tid":22630,"ts":826,"ph":"B","name":"A","args":{}},
@@ -24,7 +33,11 @@ cr.define('gpu', function() {
         {"cat":"PERF","pid":22630,"tid":22630,"ts":854,"ph":"E","name":"B","args":{}},
 
         {"cat":"PERF","pid":22630,"tid":22631,"ts":827,"ph":"B","name":"A","args":{}},
-        {"cat":"PERF","pid":22630,"tid":22631,"ts":854,"ph":"E","name":"A","args":{}}
+        {"cat":"PERF","pid":22630,"tid":22631,"ts":854,"ph":"E","name":"A","args":{}},
+
+        {"cat":"__metadata","pid":22630,"tid":22630,"ts":0,"ph":"M","name":"thread_name","args":{"name": "threadA"}},
+        {"cat":"__metadata","pid":22630,"tid":22631,"ts":0,"ph":"M","name":"thread_name","args":{"name": "threadB"}},
+        {"cat":"__metadata","pid":22630,"tid":22632,"ts":0,"ph":"M","name":"thread_name","args":{"name": "threadC"}},
       ]
     },
     {