Allow configuring CPU profiler sampling interval using public API

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 1932fb8cd767b16cbcb3faaf693283605be11381..65a2f9ab673596af3f6e1d12418e99b0a7570fb1 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -141,13 +141,11 @@ class V8_EXPORT CpuProfile {
 class V8_EXPORT CpuProfiler {
  public:
   /**
-   * A note on security tokens usage. As scripts from different
-   * origins can run inside a single V8 instance, it is possible to
-   * have functions from different security contexts intermixed in a
-   * single CPU profile. To avoid exposing function names belonging to
-   * other contexts, filtering by security token is performed while
-   * obtaining profiling results.
+   * Changes default CPU profiler sampling interval to the specified number
+   * of microseconds. Default interval is 1000us. This method must be called
+   * when there are no profiles being recorded.
    */
+  void SetSamplingInterval(int us);
 
   /**
    * Returns the number of profiles collected (doesn't include