Include thread CPU time in Timeline

runtime/vm/os_linux.cc

Index: runtime/vm/os_linux.cc
diff --git a/runtime/vm/os_linux.cc b/runtime/vm/os_linux.cc
index 0fc90c7394abdcfec135ba8152c6178edbdc0be9..7d7c7e0fc5d580f5321c9a4d199d6067dcd36fc1 100644
--- a/runtime/vm/os_linux.cc
+++ b/runtime/vm/os_linux.cc
@@ -175,6 +175,19 @@ int64_t OS::GetCurrentMonotonicMicros() {
 }
 
 
+int64_t OS::GetCurrentThreadCPUMicros() {
+  struct timespec ts;
+  if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) != 0) {
+    UNREACHABLE();
+    return -1;
+  }
+  int64_t result = ts.tv_sec;
+  result *= kMicrosecondsPerSecond;
+  result += (ts.tv_nsec / kNanosecondsPerMicrosecond);
+  return result;
+}
+
+
 void* OS::AlignedAllocate(intptr_t size, intptr_t alignment) {
   const int kMinimumAlignment = 16;
   ASSERT(Utils::IsPowerOfTwo(alignment));