Heap profiler: publish API and add test.

src/v8.cc

Index: src/v8.cc
diff --git a/src/v8.cc b/src/v8.cc
index 65ce2e1bc944c1d35d4340bf3df91c94ccac970b..23139670c3e58f55facc4fc3efdd5a1baf24c44b 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 @@ bool V8::Initialize(Deserializer* des) {
   Logger::Setup();
 
   CpuProfiler::Setup();
+  HeapProfiler::Setup();
 
   // Setup the platform OS support.
   OS::Setup();
@@ -149,6 +151,8 @@ void V8::TearDown() {
 
   Top::TearDown();
 
+  HeapProfiler::TearDown();
+
   CpuProfiler::TearDown();
 
   Heap::TearDown();