Perf Tests: Add mutex around trace events.

src/tests/perf_tests/ANGLEPerfTest.cpp

@@ -93,6 +93,8 @@ angle::TraceEventHandle AddPerfTraceEvent(angle::PlatformMethods *platform,
 
     ANGLERenderTest *renderTest = static_cast<ANGLERenderTest *>(platform->context);
 
+    std::lock_guard<std::mutex> lock(renderTest->getTraceEventMutex());
+
     uint32_t tid = renderTest->getCurrentThreadSerial();
 
     std::vector<TraceEvent> &buffer = renderTest->getTraceEventBuffer();

src/tests/perf_tests/ANGLEPerfTest.h

@@ -12,6 +12,7 @@
 
 #include <gtest/gtest.h>
 
+#include <mutex>
 #include <string>
 #include <thread>
 #include <unordered_map>
@@ -171,6 +172,7 @@ class ANGLERenderTest : public ANGLEPerfTest
     void onErrorMessage(const char *errorMessage);
 
     uint32_t getCurrentThreadSerial();
+    std::mutex &getTraceEventMutex() { return mTraceEventMutex; }
 
   protected:
     const RenderTestParams &mTestParams;
@@ -224,6 +226,7 @@ class ANGLERenderTest : public ANGLEPerfTest
     std::unique_ptr<angle::Library> mEntryPointsLib;
 
     std::vector<std::thread::id> mThreadIDs;
+    std::mutex mTraceEventMutex;
 };
 
 // Mixins.