Update V8 to r4924 as required by WebKit r61871

Change-Id: Ic819dad0c1c9e035b8ffd306c96656ba87c5e85a
diff --git a/src/v8.cc b/src/v8.cc
index 65ce2e1..2313967 100644
--- a/src/v8.cc
+++ b/src/v8.cc
@@ -32,6 +32,7 @@
 #include "serialize.h"
 #include "simulator.h"
 #include "stub-cache.h"
+#include "heap-profiler.h"
 #include "oprofile-agent.h"
 #include "log.h"
 
@@ -61,6 +62,7 @@
   Logger::Setup();
 
   CpuProfiler::Setup();
+  HeapProfiler::Setup();
 
   // Setup the platform OS support.
   OS::Setup();
@@ -149,6 +151,8 @@
 
   Top::TearDown();
 
+  HeapProfiler::TearDown();
+
   CpuProfiler::TearDown();
 
   Heap::TearDown();