Add global_context field to GlobalObject in heap profiler.

LOG=N
R=ulan@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/143263015

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18942 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap-snapshot-generator.cc

@@ -1131,9 +1131,14 @@ void V8HeapExplorer::ExtractJSObjectReferences(
     SetInternalReference(global_obj, entry,
                          "native_context", global_obj->native_context(),
                          GlobalObject::kNativeContextOffset);
+    SetInternalReference(global_obj, entry,
+                         "global_context", global_obj->global_context(),
+                         GlobalObject::kGlobalContextOffset);
     SetInternalReference(global_obj, entry,
                          "global_receiver", global_obj->global_receiver(),
                          GlobalObject::kGlobalReceiverOffset);
+    STATIC_CHECK(GlobalObject::kHeaderSize - JSObject::kHeaderSize ==
+                 4 * kPointerSize);
   } else if (obj->IsJSArrayBufferView()) {
     JSArrayBufferView* view = JSArrayBufferView::cast(obj);
     SetInternalReference(view, entry, "buffer", view->buffer(),

test/cctest/test-heap-profiler.cc

@@ -1537,6 +1537,30 @@ TEST(GlobalObjectName) {
 }
 
 
+TEST(GlobalObjectFields) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  v8::HeapProfiler* heap_profiler = env->GetIsolate()->GetHeapProfiler();
+  CompileRun("obj = {};");
+  const v8::HeapSnapshot* snapshot =
+      heap_profiler->TakeHeapSnapshot(v8_str("snapshot"));
+  CHECK(ValidateSnapshot(snapshot));
+  const v8::HeapGraphNode* global = GetGlobalObject(snapshot);
+  const v8::HeapGraphNode* builtins =
+      GetProperty(global, v8::HeapGraphEdge::kInternal, "builtins");
+  CHECK_NE(NULL, builtins);
+  const v8::HeapGraphNode* native_context =
+      GetProperty(global, v8::HeapGraphEdge::kInternal, "native_context");
+  CHECK_NE(NULL, native_context);
+  const v8::HeapGraphNode* global_context =
+      GetProperty(global, v8::HeapGraphEdge::kInternal, "global_context");
+  CHECK_NE(NULL, global_context);
+  const v8::HeapGraphNode* global_receiver =
+      GetProperty(global, v8::HeapGraphEdge::kInternal, "global_receiver");
+  CHECK_NE(NULL, global_receiver);
+}
+
+
 TEST(NoHandleLeaks) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());