perf_tests: Add missing trace event "id"

This missing identifier is used to match async trace events. Its
absence broke async trace events since their Begin/End could not
be matched correctly.

Bug: dawn:208
Change-Id: I0671af8c3cbb8ff6220adcb8ed5621b831e383c7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/12760
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

src/tests/perf_tests/DawnPerfTest.cpp

@@ -125,6 +125,7 @@ void DawnPerfTestEnvironment::DumpTraceEventsToJSONFile() const {
         value["name"] = traceEvent.name;
         value["cat"] = traceEvent.categoryName;
         value["ph"] = &phase[0];
+        value["id"] = traceEvent.id;
         value["ts"] = microseconds;
         value["pid"] = "Dawn";
 

src/tests/perf_tests/DawnPerfTestPlatform.cpp

@@ -80,7 +80,7 @@ uint64_t DawnPerfTestPlatform::AddTraceEvent(char phase,
                   "|enabled| must be the first field of the TraceCategory class.");
     const TraceCategory* category = reinterpret_cast<const TraceCategory*>(categoryGroupEnabled);
 
-    mTraceEventBuffer.emplace_back(phase, category->name, name, timestamp);
+    mTraceEventBuffer.emplace_back(phase, category->name, name, id, timestamp);
     return static_cast<uint64_t>(mTraceEventBuffer.size());
 }
 

src/tests/perf_tests/DawnPerfTestPlatform.h

@@ -32,13 +32,22 @@ class DawnPerfTestPlatform : public dawn_platform::Platform {
     struct TraceEvent final {
         TraceEvent() {
         }
-        TraceEvent(char phaseIn, const char* categoryNameIn, const char* nameIn, double timestampIn)
-            : phase(phaseIn), categoryName(categoryNameIn), name(nameIn), timestamp(timestampIn) {
+        TraceEvent(char phaseIn,
+                   const char* categoryNameIn,
+                   const char* nameIn,
+                   uint64_t idIn,
+                   double timestampIn)
+            : phase(phaseIn),
+              categoryName(categoryNameIn),
+              name(nameIn),
+              id(idIn),
+              timestamp(timestampIn) {
         }
 
         char phase = 0;
         const char* categoryName = nullptr;
         const char* name = nullptr;
+        uint64_t id = 0;
         double timestamp = 0;
     };