Include thread CPU time in Timeline

runtime/vm/os.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OS_H_
 #define VM_OS_H_
 
 #include "vm/globals.h"
 
 // Forward declarations.
@@ skipping 38 matching lines @@
 
   // Returns the current time used by the tracing infrastructure.
   static int64_t GetCurrentMonotonicMicros();
 
   // Returns the raw clock value from the monotonic clock.
   static int64_t GetCurrentMonotonicTicks();
 
   // Returns the frequency of the monotonic clock.
   static int64_t GetCurrentMonotonicFrequency();
 
+  // Returns the value of current thread's CPU usage clock in microseconds.
+  // NOTE: This clock will return different values depending on the calling
+  // thread. It is only expected to increase in value as the thread uses
+  // CPU time.
+  // NOTE: This function will return -1 on OSs that are not supported.
+  static int64_t GetCurrentThreadCPUMicros();
+
   // Returns a cleared aligned array of type T with n entries.
   // Alignment must be >= 16 and a power of two.
   template<typename T>
   static T* AllocateAlignedArray(intptr_t n, intptr_t alignment) {
     T* result = reinterpret_cast<T*>(OS::AlignedAllocate(n * sizeof(*result),
                                                          alignment));
     memset(result, 0, n * sizeof(*result));
     return result;
   }
 
@@ skipping 86 matching lines @@
   static void Shutdown();
 
   static void Abort();
 
   static void Exit(int code);
 };
 
 }  // namespace dart
 
 #endif  // VM_OS_H_