Return start/end profiling time in microseconds instead of milliseconds

include/v8-profiler.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 131 matching lines @@
     */
   int GetSamplesCount() const;
 
   /**
     * Returns profile node corresponding to the top frame the sample at
     * the given index.
     */
   const CpuProfileNode* GetSample(int index) const;
 
   /**
-    * Returns time when the profile recording started (in milliseconds
+    * Returns time when the profile recording started (in microseconds
     * since the Epoch).
     */
-  double GetStartTime() const;
+  int64_t GetStartTime() const;
 
   /**
-    * Returns time when the profile recording was stopped (in milliseconds
+    * Returns time when the profile recording was stopped (in microseconds
     * since the Epoch).
     */
-  double GetEndTime() const;
+  int64_t GetEndTime() const;
 
   /**
    * Deletes the profile and removes it from CpuProfiler's list.
    * All pointers to nodes previously returned become invalid.
    * Profiles with the same uid but obtained using different
    * security token are not deleted, but become inaccessible
    * using FindProfile method. It is embedder's responsibility
    * to call Delete on these profiles.
    */
   void Delete();
@@ skipping 424 matching lines @@
 };
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 
 
 #endif  // V8_V8_PROFILER_H_