Add snapshot mode for heap profiling.

src/log.h

Index: src/log.h
diff --git a/src/log.h b/src/log.h
index 1692e77d210de381cdb26c499cc7c65abad0fe4b..89f6cdb3915d0e69b10e4a16e61a1ce783fd6893 100644
--- a/src/log.h
+++ b/src/log.h
@@ -249,11 +249,11 @@ class Logger {
   }
 
   // Pause/Resume collection of profiling data.
-  // When data collection is paused, Tick events are discarded until
+  // When data collection is paused, CPU Tick events are discarded until
   // data collection is Resumed.
-  static bool IsProfilerPaused();
-  static void PauseProfiler();
-  static void ResumeProfiler();
+  static void PauseProfiler(int flags);
+  static void ResumeProfiler(int flags);
+  static int GetActiveProfilerModules();
 
   // If logging is performed into a memory buffer, allows to
   // retrieve previously written messages. See v8.h.