Update V8 to r7427: Initial merge by git

As required by WebKit r82507

Change-Id: I7ae83ef3f689356043b4929255b7c1dd31d8c5df
diff --git a/test/cctest/test-accessors.cc b/test/cctest/test-accessors.cc
index 25f5c39..b74f166 100644
--- a/test/cctest/test-accessors.cc
+++ b/test/cctest/test-accessors.cc
@@ -243,7 +243,7 @@
   ApiTestFuzzer::Fuzz();
   CHECK(info.This() == info.Holder());
   CHECK(info.Data()->Equals(v8::String::New("data")));
-  i::Heap::CollectAllGarbage(true);
+  HEAP->CollectAllGarbage(true);
   CHECK(info.This() == info.Holder());
   CHECK(info.Data()->Equals(v8::String::New("data")));
   return v8::Integer::New(17);
@@ -397,9 +397,9 @@
   for (int i = 0; !iter.done(); i++) {
     i::StackFrame* frame = iter.frame();
     CHECK(i != 0 || (frame->type() == i::StackFrame::EXIT));
-    CHECK(frame->code()->IsCode());
+    i::Code* code = frame->LookupCode(i::Isolate::Current());
+    CHECK(code->IsCode());
     i::Address pc = frame->pc();
-    i::Code* code = frame->code();
     CHECK(code->contains(pc));
     iter.Advance();
   }