diff --git a/test/cctest/test-alloc.cc b/test/cctest/test-alloc.cc
index 2936d6e..fcf2ce4 100644
--- a/test/cctest/test-alloc.cc
+++ b/test/cctest/test-alloc.cc
@@ -35,7 +35,7 @@
 using namespace v8::internal;
 
 
-static Object* AllocateAfterFailures() {
+static MaybeObject* AllocateAfterFailures() {
   static int attempts = 0;
   if (++attempts < 3) return Failure::RetryAfterGC();
 
@@ -60,7 +60,8 @@
   CHECK(!Heap::AllocateFixedArray(100)->IsFailure());
   CHECK(!Heap::AllocateHeapNumber(0.42)->IsFailure());
   CHECK(!Heap::AllocateArgumentsObject(Smi::FromInt(87), 10)->IsFailure());
-  Object* object = Heap::AllocateJSObject(*Top::object_function());
+  Object* object =
+      Heap::AllocateJSObject(*Top::object_function())->ToObjectChecked();
   CHECK(!Heap::CopyJSObject(JSObject::cast(object))->IsFailure());
 
   // Old data space.
@@ -111,7 +112,7 @@
 }
 
 
-static Object* TestAccessorGet(Object* object, void*) {
+static MaybeObject* TestAccessorGet(Object* object, void*) {
   return AllocateAfterFailures();
 }
 
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index fd44aec..6eb15d8 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -9278,7 +9278,9 @@
     // Inject the input as a global variable.
     i::Handle<i::String> input_name =
         i::Factory::NewStringFromAscii(i::Vector<const char>("input", 5));
-    i::Top::global_context()->global()->SetProperty(*input_name, *input_, NONE);
+    i::Top::global_context()->global()->SetProperty(*input_name,
+                                                    *input_,
+                                                    NONE)->ToObjectChecked();
 
 
     MorphThread morph_thread(this);
@@ -9750,7 +9752,7 @@
   // Set the elements to be the pixels.
   // jsobj->set_elements(*pixels);
   obj->SetIndexedPropertiesToPixelData(pixel_data, kElementCount);
-  CHECK_EQ(1, i::Smi::cast(jsobj->GetElement(1))->value());
+  CHECK_EQ(1, i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
   obj->Set(v8_str("field"), v8::Int32::New(1503));
   context->Global()->Set(v8_str("pixels"), obj);
   v8::Handle<v8::Value> result = CompileRun("pixels.field");
@@ -9802,27 +9804,34 @@
 
   i::Handle<i::Smi> value(i::Smi::FromInt(2));
   i::SetElement(jsobj, 1, value);
-  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(1))->value());
+  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
   *value.location() = i::Smi::FromInt(256);
   i::SetElement(jsobj, 1, value);
-  CHECK_EQ(255, i::Smi::cast(jsobj->GetElement(1))->value());
+  CHECK_EQ(255,
+           i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
   *value.location() = i::Smi::FromInt(-1);
   i::SetElement(jsobj, 1, value);
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(1))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[i] = (i * 65) - 109;"
                       "}"
                       "pixels[1] + pixels[6];");
   CHECK_EQ(255, result->Int32Value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(0))->value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(1))->value());
-  CHECK_EQ(21, i::Smi::cast(jsobj->GetElement(2))->value());
-  CHECK_EQ(86, i::Smi::cast(jsobj->GetElement(3))->value());
-  CHECK_EQ(151, i::Smi::cast(jsobj->GetElement(4))->value());
-  CHECK_EQ(216, i::Smi::cast(jsobj->GetElement(5))->value());
-  CHECK_EQ(255, i::Smi::cast(jsobj->GetElement(6))->value());
-  CHECK_EQ(255, i::Smi::cast(jsobj->GetElement(7))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(0)->ToObjectChecked())->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
+  CHECK_EQ(21,
+           i::Smi::cast(jsobj->GetElement(2)->ToObjectChecked())->value());
+  CHECK_EQ(86,
+           i::Smi::cast(jsobj->GetElement(3)->ToObjectChecked())->value());
+  CHECK_EQ(151,
+           i::Smi::cast(jsobj->GetElement(4)->ToObjectChecked())->value());
+  CHECK_EQ(216,
+           i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
+  CHECK_EQ(255,
+           i::Smi::cast(jsobj->GetElement(6)->ToObjectChecked())->value());
+  CHECK_EQ(255,
+           i::Smi::cast(jsobj->GetElement(7)->ToObjectChecked())->value());
   result = CompileRun("var sum = 0;"
                       "for (var i = 0; i < 8; i++) {"
                       "  sum += pixels[i];"
@@ -9835,49 +9844,50 @@
                       "}"
                       "pixels[1] + pixels[6];");
   CHECK_EQ(8, result->Int32Value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(0))->value());
-  CHECK_EQ(1, i::Smi::cast(jsobj->GetElement(1))->value());
-  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(2))->value());
-  CHECK_EQ(3, i::Smi::cast(jsobj->GetElement(3))->value());
-  CHECK_EQ(4, i::Smi::cast(jsobj->GetElement(4))->value());
-  CHECK_EQ(6, i::Smi::cast(jsobj->GetElement(5))->value());
-  CHECK_EQ(7, i::Smi::cast(jsobj->GetElement(6))->value());
-  CHECK_EQ(8, i::Smi::cast(jsobj->GetElement(7))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(0)->ToObjectChecked())->value());
+  CHECK_EQ(1, i::Smi::cast(jsobj->GetElement(1)->ToObjectChecked())->value());
+  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(2)->ToObjectChecked())->value());
+  CHECK_EQ(3, i::Smi::cast(jsobj->GetElement(3)->ToObjectChecked())->value());
+  CHECK_EQ(4, i::Smi::cast(jsobj->GetElement(4)->ToObjectChecked())->value());
+  CHECK_EQ(6, i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
+  CHECK_EQ(7, i::Smi::cast(jsobj->GetElement(6)->ToObjectChecked())->value());
+  CHECK_EQ(8, i::Smi::cast(jsobj->GetElement(7)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[7] = undefined;"
                       "}"
                       "pixels[7];");
   CHECK_EQ(0, result->Int32Value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(7))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(7)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[6] = '2.3';"
                       "}"
                       "pixels[6];");
   CHECK_EQ(2, result->Int32Value());
-  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(6))->value());
+  CHECK_EQ(2, i::Smi::cast(jsobj->GetElement(6)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[5] = NaN;"
                       "}"
                       "pixels[5];");
   CHECK_EQ(0, result->Int32Value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(5))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[8] = Infinity;"
                       "}"
                       "pixels[8];");
   CHECK_EQ(255, result->Int32Value());
-  CHECK_EQ(255, i::Smi::cast(jsobj->GetElement(8))->value());
+  CHECK_EQ(255,
+           i::Smi::cast(jsobj->GetElement(8)->ToObjectChecked())->value());
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  pixels[9] = -Infinity;"
                       "}"
                       "pixels[9];");
   CHECK_EQ(0, result->Int32Value());
-  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(9))->value());
+  CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(9)->ToObjectChecked())->value());
 
   result = CompileRun("pixels[3] = 33;"
                       "delete pixels[3];"
@@ -9987,7 +9997,8 @@
   obj->SetIndexedPropertiesToExternalArrayData(array_data,
                                                array_type,
                                                kElementCount);
-  CHECK_EQ(1, static_cast<int>(jsobj->GetElement(1)->Number()));
+  CHECK_EQ(
+      1, static_cast<int>(jsobj->GetElement(1)->ToObjectChecked()->Number()));
   obj->Set(v8_str("field"), v8::Int32::New(1503));
   context->Global()->Set(v8_str("ext_array"), obj);
   v8::Handle<v8::Value> result = CompileRun("ext_array.field");
@@ -10126,14 +10137,16 @@
                       "}"
                       "ext_array[7];");
   CHECK_EQ(0, result->Int32Value());
-  CHECK_EQ(0, static_cast<int>(jsobj->GetElement(7)->Number()));
+  CHECK_EQ(
+      0, static_cast<int>(jsobj->GetElement(7)->ToObjectChecked()->Number()));
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  ext_array[6] = '2.3';"
                       "}"
                       "ext_array[6];");
   CHECK_EQ(2, result->Int32Value());
-  CHECK_EQ(2, static_cast<int>(jsobj->GetElement(6)->Number()));
+  CHECK_EQ(
+      2, static_cast<int>(jsobj->GetElement(6)->ToObjectChecked()->Number()));
 
   if (array_type != v8::kExternalFloatArray) {
     // Though the specification doesn't state it, be explicit about
@@ -10146,7 +10159,8 @@
                         "}"
                         "ext_array[5];");
     CHECK_EQ(0, result->Int32Value());
-    CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(5))->value());
+    CHECK_EQ(0,
+             i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
 
     result = CompileRun("for (var i = 0; i < 8; i++) {"
                         "  ext_array[i] = 5;"
@@ -10156,7 +10170,8 @@
                         "}"
                         "ext_array[5];");
     CHECK_EQ(0, result->Int32Value());
-    CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(5))->value());
+    CHECK_EQ(0,
+             i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
 
     result = CompileRun("for (var i = 0; i < 8; i++) {"
                         "  ext_array[i] = 5;"
@@ -10166,7 +10181,8 @@
                         "}"
                         "ext_array[5];");
     CHECK_EQ(0, result->Int32Value());
-    CHECK_EQ(0, i::Smi::cast(jsobj->GetElement(5))->value());
+    CHECK_EQ(0,
+             i::Smi::cast(jsobj->GetElement(5)->ToObjectChecked())->value());
   }
 
   result = CompileRun("ext_array[3] = 33;"
diff --git a/test/cctest/test-assembler-arm.cc b/test/cctest/test-assembler-arm.cc
index 7c669d3..4f90b61 100644
--- a/test/cctest/test-assembler-arm.cc
+++ b/test/cctest/test-assembler-arm.cc
@@ -69,9 +69,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -105,9 +106,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -150,9 +152,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -197,9 +200,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -290,9 +294,10 @@
 
     CodeDesc desc;
     assm.GetCode(&desc);
-    Object* code = Heap::CreateCode(desc,
-                                    Code::ComputeFlags(Code::STUB),
-                                    Handle<Object>(Heap::undefined_value()));
+    Object* code = Heap::CreateCode(
+        desc,
+        Code::ComputeFlags(Code::STUB),
+        Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
     CHECK(code->IsCode());
 #ifdef DEBUG
     Code::cast(code)->Print();
@@ -341,9 +346,10 @@
 
     CodeDesc desc;
     assm.GetCode(&desc);
-    Object* code = Heap::CreateCode(desc,
-                                    Code::ComputeFlags(Code::STUB),
-                                    Handle<Object>(Heap::undefined_value()));
+    Object* code = Heap::CreateCode(
+        desc,
+        Code::ComputeFlags(Code::STUB),
+        Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
     CHECK(code->IsCode());
 #ifdef DEBUG
     Code::cast(code)->Print();
@@ -375,9 +381,10 @@
 
     CodeDesc desc;
     assm.GetCode(&desc);
-    Object* code = Heap::CreateCode(desc,
-                                    Code::ComputeFlags(Code::STUB),
-                                    Handle<Object>(Heap::undefined_value()));
+    Object* code = Heap::CreateCode(
+        desc,
+        Code::ComputeFlags(Code::STUB),
+        Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
     CHECK(code->IsCode());
 #ifdef DEBUG
     Code::cast(code)->Print();
diff --git a/test/cctest/test-assembler-ia32.cc b/test/cctest/test-assembler-ia32.cc
index b60865d..40232ef 100644
--- a/test/cctest/test-assembler-ia32.cc
+++ b/test/cctest/test-assembler-ia32.cc
@@ -71,7 +71,8 @@
   assm.GetCode(&desc);
   Object* code = Heap::CreateCode(desc,
                                   Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+                                  Handle<Object>(Heap::undefined_value()))->
+      ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -108,7 +109,8 @@
   assm.GetCode(&desc);
   Object* code = Heap::CreateCode(desc,
                                   Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+                                  Handle<Object>(Heap::undefined_value()))->
+      ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -147,9 +149,11 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
+
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -180,10 +184,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
   // don't print the code - our disassembler can't handle cvttss2si
   // instead print bytes
   Disassembler::Dump(stdout,
@@ -214,10 +218,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
   // don't print the code - our disassembler can't handle cvttsd2si
   // instead print bytes
   Disassembler::Dump(stdout,
@@ -243,10 +247,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
   F0 f = FUNCTION_CAST<F0>(code->entry());
   int res = f();
   CHECK_EQ(42, res);
@@ -280,10 +284,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
 #ifdef DEBUG
   ::printf("\n---\n");
   // don't print the code - our disassembler can't handle SSE instructions
@@ -320,10 +324,10 @@
   __ ret(0);
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
@@ -375,10 +379,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Code* code =
-      Code::cast(Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value())));
+  Code* code = Code::cast(Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked());
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
diff --git a/test/cctest/test-compiler.cc b/test/cctest/test-compiler.cc
index 96549a3..b424b7f 100644
--- a/test/cctest/test-compiler.cc
+++ b/test/cctest/test-compiler.cc
@@ -98,7 +98,7 @@
 }
 
 
-static Object* GetGlobalProperty(const char* name) {
+static MaybeObject* GetGlobalProperty(const char* name) {
   Handle<String> symbol = Factory::LookupAsciiSymbol(name);
   return Top::context()->global()->GetProperty(*symbol);
 }
@@ -140,7 +140,7 @@
   Handle<JSObject> global(Top::context()->global());
   Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
-  return GetGlobalProperty("result")->Number();
+  return GetGlobalProperty("result")->ToObjectChecked()->Number();
 }
 
 
@@ -161,7 +161,7 @@
   Handle<JSObject> global(Top::context()->global());
   Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
-  return GetGlobalProperty("result")->Number();
+  return GetGlobalProperty("result")->ToObjectChecked()->Number();
 }
 
 
@@ -181,7 +181,7 @@
   Handle<JSObject> global(Top::context()->global());
   Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
-  return GetGlobalProperty("result")->Number();
+  return GetGlobalProperty("result")->ToObjectChecked()->Number();
 }
 
 
@@ -202,7 +202,7 @@
   Handle<JSObject> global(Top::context()->global());
   Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
-  return GetGlobalProperty("result")->Number();
+  return GetGlobalProperty("result")->ToObjectChecked()->Number();
 }
 
 
@@ -256,7 +256,7 @@
   Handle<JSObject> global(Top::context()->global());
   Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
-  CHECK_EQ(511.0, GetGlobalProperty("r")->Number());
+  CHECK_EQ(511.0, GetGlobalProperty("r")->ToObjectChecked()->Number());
 }
 
 
@@ -272,7 +272,7 @@
   Handle<Object> result =
       Execution::Call(fun, global, 0, NULL, &has_pending_exception);
   CHECK(has_pending_exception);
-  CHECK_EQ(42.0, Top::pending_exception()->Number());
+  CHECK_EQ(42.0, Top::pending_exception()->ToObjectChecked()->Number());
 }
 
 
@@ -297,10 +297,10 @@
   Execution::Call(fun0, global, 0, NULL, &has_pending_exception);
   CHECK(!has_pending_exception);
 
-  Handle<Object> fun1 =
-      Handle<Object>(
-          Top::context()->global()->GetProperty(
-              *Factory::LookupAsciiSymbol("foo")));
+  Object* foo_symbol = Factory::LookupAsciiSymbol("foo")->ToObjectChecked();
+  MaybeObject* fun1_object =
+      Top::context()->global()->GetProperty(String::cast(foo_symbol));
+  Handle<Object> fun1(fun1_object->ToObjectChecked());
   CHECK(fun1->IsJSFunction());
 
   Object** argv[1] = {
diff --git a/test/cctest/test-disasm-ia32.cc b/test/cctest/test-disasm-ia32.cc
index b53eaaa..5cd56ac 100644
--- a/test/cctest/test-disasm-ia32.cc
+++ b/test/cctest/test-disasm-ia32.cc
@@ -438,9 +438,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 #ifdef DEBUG
   Code::cast(code)->Print();
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index 126ac21..94d0555 100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -58,7 +58,7 @@
 
 
 static void CheckNumber(double value, const char* string) {
-  Object* obj = Heap::NumberFromDouble(value);
+  Object* obj = Heap::NumberFromDouble(value)->ToObjectChecked();
   CHECK(obj->IsNumber());
   bool exc;
   Object* print_string = *Execution::ToString(Handle<Object>(obj), &exc);
@@ -76,9 +76,10 @@
 
   CodeDesc desc;
   assm.GetCode(&desc);
-  Object* code = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* code = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(code->IsCode());
 
   HeapObject* obj = HeapObject::cast(code);
@@ -89,9 +90,10 @@
     CHECK_EQ(code, found);
   }
 
-  Object* copy = Heap::CreateCode(desc,
-                                  Code::ComputeFlags(Code::STUB),
-                                  Handle<Object>(Heap::undefined_value()));
+  Object* copy = Heap::CreateCode(
+      desc,
+      Code::ComputeFlags(Code::STUB),
+      Handle<Object>(Heap::undefined_value()))->ToObjectChecked();
   CHECK(copy->IsCode());
   HeapObject* obj_copy = HeapObject::cast(copy);
   Object* not_right = Heap::FindCodeObject(obj_copy->address() +
@@ -104,40 +106,42 @@
   InitializeVM();
 
   v8::HandleScope sc;
-  Object* value = Heap::NumberFromDouble(1.000123);
+  Object* value = Heap::NumberFromDouble(1.000123)->ToObjectChecked();
   CHECK(value->IsHeapNumber());
   CHECK(value->IsNumber());
   CHECK_EQ(1.000123, value->Number());
 
-  value = Heap::NumberFromDouble(1.0);
+  value = Heap::NumberFromDouble(1.0)->ToObjectChecked();
   CHECK(value->IsSmi());
   CHECK(value->IsNumber());
   CHECK_EQ(1.0, value->Number());
 
-  value = Heap::NumberFromInt32(1024);
+  value = Heap::NumberFromInt32(1024)->ToObjectChecked();
   CHECK(value->IsSmi());
   CHECK(value->IsNumber());
   CHECK_EQ(1024.0, value->Number());
 
-  value = Heap::NumberFromInt32(Smi::kMinValue);
+  value = Heap::NumberFromInt32(Smi::kMinValue)->ToObjectChecked();
   CHECK(value->IsSmi());
   CHECK(value->IsNumber());
   CHECK_EQ(Smi::kMinValue, Smi::cast(value)->value());
 
-  value = Heap::NumberFromInt32(Smi::kMaxValue);
+  value = Heap::NumberFromInt32(Smi::kMaxValue)->ToObjectChecked();
   CHECK(value->IsSmi());
   CHECK(value->IsNumber());
   CHECK_EQ(Smi::kMaxValue, Smi::cast(value)->value());
 
 #ifndef V8_TARGET_ARCH_X64
   // TODO(lrn): We need a NumberFromIntptr function in order to test this.
-  value = Heap::NumberFromInt32(Smi::kMinValue - 1);
+  value = Heap::NumberFromInt32(Smi::kMinValue - 1)->ToObjectChecked();
   CHECK(value->IsHeapNumber());
   CHECK(value->IsNumber());
   CHECK_EQ(static_cast<double>(Smi::kMinValue - 1), value->Number());
 #endif
 
-  value = Heap::NumberFromUint32(static_cast<uint32_t>(Smi::kMaxValue) + 1);
+  MaybeObject* maybe_value =
+      Heap::NumberFromUint32(static_cast<uint32_t>(Smi::kMaxValue) + 1);
+  value = maybe_value->ToObjectChecked();
   CHECK(value->IsHeapNumber());
   CHECK(value->IsNumber());
   CHECK_EQ(static_cast<double>(static_cast<uint32_t>(Smi::kMaxValue) + 1),
@@ -208,11 +212,13 @@
     Handle<Map> initial_map =
         Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
     function->set_initial_map(*initial_map);
-    Top::context()->global()->SetProperty(*name, *function, NONE);
+    Top::context()->global()->SetProperty(*name,
+                                          *function,
+                                          NONE)->ToObjectChecked();
     // Allocate an object.  Unrooted after leaving the scope.
     Handle<JSObject> obj = Factory::NewJSObject(function);
-    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
-    obj->SetProperty(*prop_namex, Smi::FromInt(24), NONE);
+    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE)->ToObjectChecked();
+    obj->SetProperty(*prop_namex, Smi::FromInt(24), NONE)->ToObjectChecked();
 
     CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
     CHECK_EQ(Smi::FromInt(24), obj->GetProperty(*prop_namex));
@@ -223,7 +229,8 @@
   // Function should be alive.
   CHECK(Top::context()->global()->HasLocalProperty(*name));
   // Check function is retained.
-  Object* func_value = Top::context()->global()->GetProperty(*name);
+  Object* func_value =
+      Top::context()->global()->GetProperty(*name)->ToObjectChecked();
   CHECK(func_value->IsJSFunction());
   Handle<JSFunction> function(JSFunction::cast(func_value));
 
@@ -231,18 +238,22 @@
     HandleScope inner_scope;
     // Allocate another object, make it reachable from global.
     Handle<JSObject> obj = Factory::NewJSObject(function);
-    Top::context()->global()->SetProperty(*obj_name, *obj, NONE);
-    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
+    Top::context()->global()->SetProperty(*obj_name,
+                                          *obj,
+                                          NONE)->ToObjectChecked();
+    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE)->ToObjectChecked();
   }
 
   // After gc, it should survive.
   Heap::CollectGarbage(NEW_SPACE);
 
   CHECK(Top::context()->global()->HasLocalProperty(*obj_name));
-  CHECK(Top::context()->global()->GetProperty(*obj_name)->IsJSObject());
-  JSObject* obj =
-      JSObject::cast(Top::context()->global()->GetProperty(*obj_name));
-  CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
+  CHECK(Top::context()->global()->GetProperty(*obj_name)->ToObjectChecked()->
+            IsJSObject());
+  Object* obj =
+      Top::context()->global()->GetProperty(*obj_name)->ToObjectChecked();
+  JSObject* js_obj = JSObject::cast(obj);
+  CHECK_EQ(Smi::FromInt(23), js_obj->GetProperty(*prop_name));
 }
 
 
@@ -494,12 +505,14 @@
 
 static void CheckSymbols(const char** strings) {
   for (const char* string = *strings; *strings != 0; string = *strings++) {
-    Object* a = Heap::LookupAsciiSymbol(string);
+    Object* a;
+    MaybeObject* maybe_a = Heap::LookupAsciiSymbol(string);
     // LookupAsciiSymbol may return a failure if a GC is needed.
-    if (a->IsFailure()) continue;
+    if (!maybe_a->ToObject(&a)) continue;
     CHECK(a->IsSymbol());
-    Object* b = Heap::LookupAsciiSymbol(string);
-    if (b->IsFailure()) continue;
+    Object* b;
+    MaybeObject* maybe_b = Heap::LookupAsciiSymbol(string);
+    if (!maybe_b->ToObject(&b)) continue;
     CHECK_EQ(b, a);
     CHECK(String::cast(b)->IsEqualTo(CStrVector(string)));
   }
@@ -527,10 +540,12 @@
 
   Handle<String> prop_name = Factory::LookupAsciiSymbol("theSlot");
   Handle<JSObject> obj = Factory::NewJSObject(function);
-  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
+  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE)->ToObjectChecked();
   CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
   // Check that we can add properties to function objects.
-  function->SetProperty(*prop_name, Smi::FromInt(24), NONE);
+  function->SetProperty(*prop_name,
+                        Smi::FromInt(24),
+                        NONE)->ToObjectChecked();
   CHECK_EQ(Smi::FromInt(24), function->GetProperty(*prop_name));
 }
 
@@ -540,8 +555,9 @@
 
   v8::HandleScope sc;
   String* object_symbol = String::cast(Heap::Object_symbol());
-  JSFunction* object_function =
-      JSFunction::cast(Top::context()->global()->GetProperty(object_symbol));
+  Object* raw_object =
+      Top::context()->global()->GetProperty(object_symbol)->ToObjectChecked();
+  JSFunction* object_function = JSFunction::cast(raw_object);
   Handle<JSFunction> constructor(object_function);
   Handle<JSObject> obj = Factory::NewJSObject(constructor);
   Handle<String> first = Factory::LookupAsciiSymbol("first");
@@ -551,7 +567,7 @@
   CHECK(!obj->HasLocalProperty(*first));
 
   // add first
-  obj->SetProperty(*first, Smi::FromInt(1), NONE);
+  obj->SetProperty(*first, Smi::FromInt(1), NONE)->ToObjectChecked();
   CHECK(obj->HasLocalProperty(*first));
 
   // delete first
@@ -559,8 +575,8 @@
   CHECK(!obj->HasLocalProperty(*first));
 
   // add first and then second
-  obj->SetProperty(*first, Smi::FromInt(1), NONE);
-  obj->SetProperty(*second, Smi::FromInt(2), NONE);
+  obj->SetProperty(*first, Smi::FromInt(1), NONE)->ToObjectChecked();
+  obj->SetProperty(*second, Smi::FromInt(2), NONE)->ToObjectChecked();
   CHECK(obj->HasLocalProperty(*first));
   CHECK(obj->HasLocalProperty(*second));
 
@@ -572,8 +588,8 @@
   CHECK(!obj->HasLocalProperty(*second));
 
   // add first and then second
-  obj->SetProperty(*first, Smi::FromInt(1), NONE);
-  obj->SetProperty(*second, Smi::FromInt(2), NONE);
+  obj->SetProperty(*first, Smi::FromInt(1), NONE)->ToObjectChecked();
+  obj->SetProperty(*second, Smi::FromInt(2), NONE)->ToObjectChecked();
   CHECK(obj->HasLocalProperty(*first));
   CHECK(obj->HasLocalProperty(*second));
 
@@ -587,14 +603,14 @@
   // check string and symbol match
   static const char* string1 = "fisk";
   Handle<String> s1 = Factory::NewStringFromAscii(CStrVector(string1));
-  obj->SetProperty(*s1, Smi::FromInt(1), NONE);
+  obj->SetProperty(*s1, Smi::FromInt(1), NONE)->ToObjectChecked();
   Handle<String> s1_symbol = Factory::LookupAsciiSymbol(string1);
   CHECK(obj->HasLocalProperty(*s1_symbol));
 
   // check symbol and string match
   static const char* string2 = "fugl";
   Handle<String> s2_symbol = Factory::LookupAsciiSymbol(string2);
-  obj->SetProperty(*s2_symbol, Smi::FromInt(1), NONE);
+  obj->SetProperty(*s2_symbol, Smi::FromInt(1), NONE)->ToObjectChecked();
   Handle<String> s2 = Factory::NewStringFromAscii(CStrVector(string2));
   CHECK(obj->HasLocalProperty(*s2));
 }
@@ -615,7 +631,7 @@
   Handle<JSObject> obj = Factory::NewJSObject(function);
 
   // Set a propery
-  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
+  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE)->ToObjectChecked();
   CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
 
   // Check the map has changed
@@ -628,33 +644,31 @@
 
   v8::HandleScope sc;
   Handle<String> name = Factory::LookupAsciiSymbol("Array");
+  Object* raw_object =
+      Top::context()->global()->GetProperty(*name)->ToObjectChecked();
   Handle<JSFunction> function = Handle<JSFunction>(
-      JSFunction::cast(Top::context()->global()->GetProperty(*name)));
+      JSFunction::cast(raw_object));
 
   // Allocate the object.
   Handle<JSObject> object = Factory::NewJSObject(function);
   Handle<JSArray> array = Handle<JSArray>::cast(object);
-  Object* ok = array->Initialize(0);
   // We just initialized the VM, no heap allocation failure yet.
-  CHECK(!ok->IsFailure());
+  Object* ok = array->Initialize(0)->ToObjectChecked();
 
   // Set array length to 0.
-  ok = array->SetElementsLength(Smi::FromInt(0));
-  CHECK(!ok->IsFailure());
+  ok = array->SetElementsLength(Smi::FromInt(0))->ToObjectChecked();
   CHECK_EQ(Smi::FromInt(0), array->length());
   CHECK(array->HasFastElements());  // Must be in fast mode.
 
   // array[length] = name.
-  ok = array->SetElement(0, *name);
-  CHECK(!ok->IsFailure());
+  ok = array->SetElement(0, *name)->ToObjectChecked();
   CHECK_EQ(Smi::FromInt(1), array->length());
   CHECK_EQ(array->GetElement(0), *name);
 
   // Set array length with larger than smi value.
   Handle<Object> length =
       Factory::NewNumberFromUint(static_cast<uint32_t>(Smi::kMaxValue) + 1);
-  ok = array->SetElementsLength(*length);
-  CHECK(!ok->IsFailure());
+  ok = array->SetElementsLength(*length)->ToObjectChecked();
 
   uint32_t int_length = 0;
   CHECK(length->ToArrayIndex(&int_length));
@@ -662,8 +676,7 @@
   CHECK(array->HasDictionaryElements());  // Must be in slow mode.
 
   // array[length] = name.
-  ok = array->SetElement(int_length, *name);
-  CHECK(!ok->IsFailure());
+  ok = array->SetElement(int_length, *name)->ToObjectChecked();
   uint32_t new_int_length = 0;
   CHECK(array->length()->ToArrayIndex(&new_int_length));
   CHECK_EQ(static_cast<double>(int_length), new_int_length - 1);
@@ -677,21 +690,20 @@
 
   v8::HandleScope sc;
   String* object_symbol = String::cast(Heap::Object_symbol());
-  JSFunction* object_function =
-      JSFunction::cast(Top::context()->global()->GetProperty(object_symbol));
+  Object* raw_object =
+      Top::context()->global()->GetProperty(object_symbol)->ToObjectChecked();
+  JSFunction* object_function = JSFunction::cast(raw_object);
   Handle<JSFunction> constructor(object_function);
   Handle<JSObject> obj = Factory::NewJSObject(constructor);
   Handle<String> first = Factory::LookupAsciiSymbol("first");
   Handle<String> second = Factory::LookupAsciiSymbol("second");
 
-  obj->SetProperty(*first, Smi::FromInt(1), NONE);
-  obj->SetProperty(*second, Smi::FromInt(2), NONE);
+  obj->SetProperty(*first, Smi::FromInt(1), NONE)->ToObjectChecked();
+  obj->SetProperty(*second, Smi::FromInt(2), NONE)->ToObjectChecked();
 
-  Object* ok = obj->SetElement(0, *first);
-  CHECK(!ok->IsFailure());
+  Object* ok = obj->SetElement(0, *first)->ToObjectChecked();
 
-  ok = obj->SetElement(1, *second);
-  CHECK(!ok->IsFailure());
+  ok = obj->SetElement(1, *second)->ToObjectChecked();
 
   // Make the clone.
   Handle<JSObject> clone = Copy(obj);
@@ -704,13 +716,11 @@
   CHECK_EQ(obj->GetProperty(*second), clone->GetProperty(*second));
 
   // Flip the values.
-  clone->SetProperty(*first, Smi::FromInt(2), NONE);
-  clone->SetProperty(*second, Smi::FromInt(1), NONE);
+  clone->SetProperty(*first, Smi::FromInt(2), NONE)->ToObjectChecked();
+  clone->SetProperty(*second, Smi::FromInt(1), NONE)->ToObjectChecked();
 
-  ok = clone->SetElement(0, *second);
-  CHECK(!ok->IsFailure());
-  ok = clone->SetElement(1, *first);
-  CHECK(!ok->IsFailure());
+  ok = clone->SetElement(0, *second)->ToObjectChecked();
+  ok = clone->SetElement(1, *first)->ToObjectChecked();
 
   CHECK_EQ(obj->GetElement(1), clone->GetElement(0));
   CHECK_EQ(obj->GetElement(0), clone->GetElement(1));
@@ -836,7 +846,7 @@
       kPointerSize;
   CHECK_EQ(bytes_to_allocate, FixedArray::SizeFor(n_elements));
   FixedArray* array = FixedArray::cast(
-      Heap::AllocateFixedArray(n_elements));
+      Heap::AllocateFixedArray(n_elements)->ToObjectChecked());
 
   int index = n_elements - 1;
   CHECK_EQ(flags_ptr,
@@ -908,8 +918,8 @@
   Address* limit_addr = new_space->allocation_limit_address();
   while ((*limit_addr - *top_addr) > allocation_amount) {
     CHECK(!Heap::always_allocate());
-    Object* array = Heap::AllocateFixedArray(allocation_len);
-    CHECK(!array->IsFailure());
+    Object* array =
+        Heap::AllocateFixedArray(allocation_len)->ToObjectChecked();
     CHECK(new_space->Contains(array));
   }
 
@@ -919,12 +929,11 @@
   CHECK(fixed_array_len < FixedArray::kMaxLength);
 
   CHECK(!Heap::always_allocate());
-  Object* array = Heap::AllocateFixedArray(fixed_array_len);
-  CHECK(!array->IsFailure());
+  Object* array =
+      Heap::AllocateFixedArray(fixed_array_len)->ToObjectChecked();
   CHECK(new_space->Contains(array));
 
-  Object* object = Heap::AllocateJSObjectFromMap(*my_map);
-  CHECK(!object->IsFailure());
+  Object* object = Heap::AllocateJSObjectFromMap(*my_map)->ToObjectChecked();
   CHECK(new_space->Contains(object));
   JSObject* jsobject = JSObject::cast(object);
   CHECK_EQ(0, FixedArray::cast(jsobject->elements())->length());
@@ -938,8 +947,7 @@
   // in old pointer space.
   Address old_pointer_space_top = Heap::old_pointer_space()->top();
   AlwaysAllocateScope aa_scope;
-  Object* clone_obj = Heap::CopyJSObject(jsobject);
-  CHECK(!object->IsFailure());
+  Object* clone_obj = Heap::CopyJSObject(jsobject)->ToObjectChecked();
   JSObject* clone = JSObject::cast(clone_obj);
   if (clone->address() != old_pointer_space_top) {
     // Alas, got allocated from free list, we cannot do checks.
@@ -973,7 +981,8 @@
   CompileRun(source);
 
   // Check function is compiled.
-  Object* func_value = Top::context()->global()->GetProperty(*foo_name);
+  Object* func_value =
+      Top::context()->global()->GetProperty(*foo_name)->ToObjectChecked();
   CHECK(func_value->IsJSFunction());
   Handle<JSFunction> function(JSFunction::cast(func_value));
   CHECK(function->shared()->is_compiled());
diff --git a/test/cctest/test-log-stack-tracer.cc b/test/cctest/test-log-stack-tracer.cc
index 7d7bd40..65be6bd 100644
--- a/test/cctest/test-log-stack-tracer.cc
+++ b/test/cctest/test-log-stack-tracer.cc
@@ -199,13 +199,6 @@
 }
 
 
-static Handle<JSFunction> CompileFunction(const char* source) {
-  Handle<JSFunction> result(JSFunction::cast(
-      *v8::Utils::OpenHandle(*Script::Compile(String::New(source)))));
-  return result;
-}
-
-
 static void CheckJSFunctionAtAddress(const char* func_name, Address addr) {
   i::Object* obj = i::HeapObject::FromAddress(addr);
   CHECK(obj->IsJSFunction());
@@ -218,16 +211,6 @@
 }
 
 
-static void SetGlobalProperty(const char* name, Local<Value> value) {
-  env->Global()->Set(String::New(name), value);
-}
-
-
-static Handle<v8::internal::String> NewString(const char* s) {
-  return i::Factory::NewStringFromAscii(i::CStrVector(s));
-}
-
-
 // This C++ function is called as a constructor, to grab the frame pointer
 // from the calling function.  When this function runs, the stack contains
 // a C_Entry frame and a Construct frame above the calling function's frame.
@@ -273,25 +256,18 @@
                                       const char* trace_func_name) {
   i::EmbeddedVector<char, 256> trace_call_buf;
   i::OS::SNPrintF(trace_call_buf,
-                  "fp = new FPGrabber(); %s(fp.low_bits, fp.high_bits);",
-                  trace_func_name);
+                  "function %s() {"
+                  "  fp = new FPGrabber();"
+                  "  %s(fp.low_bits, fp.high_bits);"
+                  "}",
+                  func_name, trace_func_name);
 
   // Create the FPGrabber function, which grabs the caller's frame pointer
   // when called as a constructor.
   CreateFramePointerGrabberConstructor("FPGrabber");
 
   // Compile the script.
-  Handle<JSFunction> func = CompileFunction(trace_call_buf.start());
-  CHECK(!func.is_null());
-  func->shared()->set_name(*NewString(func_name));
-
-#ifdef DEBUG
-  v8::internal::Code* func_code = func->code();
-  CHECK(func_code->IsCode());
-  func_code->Print();
-#endif
-
-  SetGlobalProperty(func_name, v8::ToApi<Value>(func));
+  CompileRun(trace_call_buf.start());
 }
 
 
diff --git a/test/cctest/test-log.cc b/test/cctest/test-log.cc
index 16d0f00..7168737 100644
--- a/test/cctest/test-log.cc
+++ b/test/cctest/test-log.cc
@@ -337,8 +337,8 @@
 }
 
 
-// Profiling multiple threads that use V8 is currently only available on Linux.
-#ifdef __linux__
+// BUG(913). Need to implement support for profiling multiple VM threads.
+#if 0
 
 namespace {
 
diff --git a/test/cctest/test-mark-compact.cc b/test/cctest/test-mark-compact.cc
index 531b1f7..ea5afec 100644
--- a/test/cctest/test-mark-compact.cc
+++ b/test/cctest/test-mark-compact.cc
@@ -85,8 +85,7 @@
   int array_size =
       (Heap::MaxObjectSizeInPagedSpace() - FixedArray::kHeaderSize) /
       (kPointerSize * 4);
-  Object* obj = Heap::AllocateFixedArray(array_size);
-  CHECK(!obj->IsFailure());
+  Object* obj = Heap::AllocateFixedArray(array_size)->ToObjectChecked();
 
   Handle<FixedArray> array(FixedArray::cast(obj));
 
@@ -116,7 +115,7 @@
   // Allocate a big Fixed array in the new space.
   int size = (Heap::MaxObjectSizeInPagedSpace() - FixedArray::kHeaderSize) /
       kPointerSize;
-  Object* obj = Heap::AllocateFixedArray(size);
+  Object* obj = Heap::AllocateFixedArray(size)->ToObjectChecked();
 
   Handle<FixedArray> array(FixedArray::cast(obj));
 
@@ -126,8 +125,10 @@
   // Allocate objects in the old space until out of memory.
   FixedArray* host = *array;
   while (true) {
-    Object* obj = Heap::AllocateFixedArray(100, TENURED);
-    if (obj->IsFailure()) break;
+    Object* obj;
+    { MaybeObject* maybe_obj = Heap::AllocateFixedArray(100, TENURED);
+      if (!maybe_obj->ToObject(&obj)) break;
+    }
 
     host->set(0, obj);
     host = FixedArray::cast(obj);
@@ -151,59 +152,75 @@
   // keep allocating garbage in new space until it fails
   const int ARRAY_SIZE = 100;
   Object* array;
+  MaybeObject* maybe_array;
   do {
-    array = Heap::AllocateFixedArray(ARRAY_SIZE);
-  } while (!array->IsFailure());
+    maybe_array = Heap::AllocateFixedArray(ARRAY_SIZE);
+  } while (maybe_array->ToObject(&array));
   Heap::CollectGarbage(NEW_SPACE);
 
-  array = Heap::AllocateFixedArray(ARRAY_SIZE);
-  CHECK(!array->IsFailure());
+  array = Heap::AllocateFixedArray(ARRAY_SIZE)->ToObjectChecked();
 
   // keep allocating maps until it fails
   Object* mapp;
+  MaybeObject* maybe_mapp;
   do {
-    mapp = Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
-  } while (!mapp->IsFailure());
+    maybe_mapp = Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
+  } while (maybe_mapp->ToObject(&mapp));
   Heap::CollectGarbage(MAP_SPACE);
-  mapp = Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
-  CHECK(!mapp->IsFailure());
+  mapp = Heap::AllocateMap(JS_OBJECT_TYPE,
+                           JSObject::kHeaderSize)->ToObjectChecked();
 
   // allocate a garbage
-  String* func_name = String::cast(Heap::LookupAsciiSymbol("theFunction"));
-  SharedFunctionInfo* function_share =
-    SharedFunctionInfo::cast(Heap::AllocateSharedFunctionInfo(func_name));
-  JSFunction* function =
-    JSFunction::cast(Heap::AllocateFunction(*Top::function_map(),
-                                            function_share,
-                                            Heap::undefined_value()));
+  String* func_name =
+      String::cast(Heap::LookupAsciiSymbol("theFunction")->ToObjectChecked());
+  SharedFunctionInfo* function_share = SharedFunctionInfo::cast(
+      Heap::AllocateSharedFunctionInfo(func_name)->ToObjectChecked());
+  JSFunction* function = JSFunction::cast(
+      Heap::AllocateFunction(*Top::function_map(),
+                             function_share,
+                             Heap::undefined_value())->ToObjectChecked());
   Map* initial_map =
-      Map::cast(Heap::AllocateMap(JS_OBJECT_TYPE, JSObject::kHeaderSize));
+      Map::cast(Heap::AllocateMap(JS_OBJECT_TYPE,
+                                  JSObject::kHeaderSize)->ToObjectChecked());
   function->set_initial_map(initial_map);
-  Top::context()->global()->SetProperty(func_name, function, NONE);
+  Top::context()->global()->SetProperty(func_name,
+                                        function,
+                                        NONE)->ToObjectChecked();
 
-  JSObject* obj = JSObject::cast(Heap::AllocateJSObject(function));
+  JSObject* obj =
+      JSObject::cast(Heap::AllocateJSObject(function)->ToObjectChecked());
   Heap::CollectGarbage(OLD_POINTER_SPACE);
 
-  func_name = String::cast(Heap::LookupAsciiSymbol("theFunction"));
+  func_name =
+      String::cast(Heap::LookupAsciiSymbol("theFunction")->ToObjectChecked());
   CHECK(Top::context()->global()->HasLocalProperty(func_name));
-  Object* func_value = Top::context()->global()->GetProperty(func_name);
+  Object* func_value =
+      Top::context()->global()->GetProperty(func_name)->ToObjectChecked();
   CHECK(func_value->IsJSFunction());
   function = JSFunction::cast(func_value);
 
-  obj = JSObject::cast(Heap::AllocateJSObject(function));
-  String* obj_name = String::cast(Heap::LookupAsciiSymbol("theObject"));
-  Top::context()->global()->SetProperty(obj_name, obj, NONE);
-  String* prop_name = String::cast(Heap::LookupAsciiSymbol("theSlot"));
-  obj->SetProperty(prop_name, Smi::FromInt(23), NONE);
+  obj = JSObject::cast(Heap::AllocateJSObject(function)->ToObjectChecked());
+  String* obj_name =
+      String::cast(Heap::LookupAsciiSymbol("theObject")->ToObjectChecked());
+  Top::context()->global()->SetProperty(obj_name,
+                                        obj,
+                                        NONE)->ToObjectChecked();
+  String* prop_name =
+      String::cast(Heap::LookupAsciiSymbol("theSlot")->ToObjectChecked());
+  obj->SetProperty(prop_name, Smi::FromInt(23), NONE)->ToObjectChecked();
 
   Heap::CollectGarbage(OLD_POINTER_SPACE);
 
-  obj_name = String::cast(Heap::LookupAsciiSymbol("theObject"));
+  obj_name =
+      String::cast(Heap::LookupAsciiSymbol("theObject")->ToObjectChecked());
   CHECK(Top::context()->global()->HasLocalProperty(obj_name));
-  CHECK(Top::context()->global()->GetProperty(obj_name)->IsJSObject());
-  obj = JSObject::cast(Top::context()->global()->GetProperty(obj_name));
-  prop_name = String::cast(Heap::LookupAsciiSymbol("theSlot"));
-  CHECK(obj->GetProperty(prop_name) == Smi::FromInt(23));
+  CHECK(Top::context()->global()->
+            GetProperty(obj_name)->ToObjectChecked()->IsJSObject());
+  obj = JSObject::cast(
+      Top::context()->global()->GetProperty(obj_name)->ToObjectChecked());
+  prop_name =
+      String::cast(Heap::LookupAsciiSymbol("theSlot")->ToObjectChecked());
+  CHECK(obj->GetProperty(prop_name)->ToObjectChecked() == Smi::FromInt(23));
 }
 
 
@@ -283,9 +300,9 @@
   v8::HandleScope handle_scope;
 
   Handle<Object> g1s1 =
-    GlobalHandles::Create(Heap::AllocateFixedArray(1));
+    GlobalHandles::Create(Heap::AllocateFixedArray(1)->ToObjectChecked());
   Handle<Object> g1s2 =
-    GlobalHandles::Create(Heap::AllocateFixedArray(1));
+    GlobalHandles::Create(Heap::AllocateFixedArray(1)->ToObjectChecked());
   GlobalHandles::MakeWeak(g1s1.location(),
                           reinterpret_cast<void*>(1234),
                           &WeakPointerCallback);
@@ -294,9 +311,9 @@
                           &WeakPointerCallback);
 
   Handle<Object> g2s1 =
-    GlobalHandles::Create(Heap::AllocateFixedArray(1));
+    GlobalHandles::Create(Heap::AllocateFixedArray(1)->ToObjectChecked());
   Handle<Object> g2s2 =
-    GlobalHandles::Create(Heap::AllocateFixedArray(1));
+    GlobalHandles::Create(Heap::AllocateFixedArray(1)->ToObjectChecked());
   GlobalHandles::MakeWeak(g2s1.location(),
                           reinterpret_cast<void*>(1234),
                           &WeakPointerCallback);
diff --git a/test/cctest/test-serialize.cc b/test/cctest/test-serialize.cc
index 20fb2fe..6a513e5 100644
--- a/test/cctest/test-serialize.cc
+++ b/test/cctest/test-serialize.cc
@@ -576,7 +576,8 @@
     for (int i = 0;
          i + kSmallFixedArraySize <= new_space_size;
          i += kSmallFixedArraySize) {
-      Object* obj = Heap::AllocateFixedArray(kSmallFixedArrayLength);
+      Object* obj =
+          Heap::AllocateFixedArray(kSmallFixedArrayLength)->ToObjectChecked();
       if (new_last != NULL) {
         CHECK(reinterpret_cast<char*>(obj) ==
               reinterpret_cast<char*>(new_last) + kSmallFixedArraySize);
@@ -588,7 +589,8 @@
     for (int i = 0;
          i + kSmallFixedArraySize <= size;
          i += kSmallFixedArraySize) {
-      Object* obj = Heap::AllocateFixedArray(kSmallFixedArrayLength, TENURED);
+      Object* obj = Heap::AllocateFixedArray(kSmallFixedArrayLength,
+                                             TENURED)->ToObjectChecked();
       int old_page_fullness = i % Page::kPageSize;
       int page_fullness = (i + kSmallFixedArraySize) % Page::kPageSize;
       if (page_fullness < old_page_fullness ||
@@ -605,7 +607,8 @@
 
     Object* data_last = NULL;
     for (int i = 0; i + kSmallStringSize <= size; i += kSmallStringSize) {
-      Object* obj = Heap::AllocateRawAsciiString(kSmallStringLength, TENURED);
+      Object* obj = Heap::AllocateRawAsciiString(kSmallStringLength,
+                                                 TENURED)->ToObjectChecked();
       int old_page_fullness = i % Page::kPageSize;
       int page_fullness = (i + kSmallStringSize) % Page::kPageSize;
       if (page_fullness < old_page_fullness ||
@@ -622,7 +625,8 @@
 
     Object* map_last = NULL;
     for (int i = 0; i + kMapSize <= size; i += kMapSize) {
-      Object* obj = Heap::AllocateMap(JS_OBJECT_TYPE, 42 * kPointerSize);
+      Object* obj = Heap::AllocateMap(JS_OBJECT_TYPE,
+                                      42 * kPointerSize)->ToObjectChecked();
       int old_page_fullness = i % Page::kPageSize;
       int page_fullness = (i + kMapSize) % Page::kPageSize;
       if (page_fullness < old_page_fullness ||
@@ -644,7 +648,7 @@
       int large_object_array_length =
           (size - FixedArray::kHeaderSize) / kPointerSize;
       Object* obj = Heap::AllocateFixedArray(large_object_array_length,
-                                             TENURED);
+                                             TENURED)->ToObjectChecked();
       CHECK(!obj->IsFailure());
     }
   }
diff --git a/test/cctest/test-spaces.cc b/test/cctest/test-spaces.cc
index db8c54f..06f1bfa 100644
--- a/test/cctest/test-spaces.cc
+++ b/test/cctest/test-spaces.cc
@@ -160,8 +160,8 @@
   CHECK(new_space.HasBeenSetup());
 
   while (new_space.Available() >= Page::kMaxHeapObjectSize) {
-    Object* obj = new_space.AllocateRaw(Page::kMaxHeapObjectSize);
-    CHECK(!obj->IsFailure());
+    Object* obj =
+        new_space.AllocateRaw(Page::kMaxHeapObjectSize)->ToObjectUnchecked();
     CHECK(new_space.Contains(HeapObject::cast(obj)));
   }
 
@@ -188,8 +188,7 @@
   CHECK(s->Setup(start, size));
 
   while (s->Available() > 0) {
-    Object* obj = s->AllocateRaw(Page::kMaxHeapObjectSize);
-    CHECK(!obj->IsFailure());
+    s->AllocateRaw(Page::kMaxHeapObjectSize)->ToObjectUnchecked();
   }
 
   s->TearDown();
@@ -207,8 +206,7 @@
   Map* faked_map = reinterpret_cast<Map*>(HeapObject::FromAddress(0));
   int lo_size = Page::kPageSize;
 
-  Object* obj = lo->AllocateRaw(lo_size);
-  CHECK(!obj->IsFailure());
+  Object* obj = lo->AllocateRaw(lo_size)->ToObjectUnchecked();
   CHECK(obj->IsHeapObject());
 
   HeapObject* ho = HeapObject::cast(obj);
@@ -222,16 +220,16 @@
 
   while (true) {
     intptr_t available = lo->Available();
-    obj = lo->AllocateRaw(lo_size);
-    if (obj->IsFailure()) break;
+    { MaybeObject* maybe_obj = lo->AllocateRaw(lo_size);
+      if (!maybe_obj->ToObject(&obj)) break;
+    }
     HeapObject::cast(obj)->set_map(faked_map);
     CHECK(lo->Available() < available);
   };
 
   CHECK(!lo->IsEmpty());
 
-  obj = lo->AllocateRaw(lo_size);
-  CHECK(obj->IsFailure());
+  CHECK(lo->AllocateRaw(lo_size)->IsFailure());
 
   lo->TearDown();
   delete lo;
diff --git a/test/cctest/test-strings.cc b/test/cctest/test-strings.cc
index 3a9e4da..3f02b32 100644
--- a/test/cctest/test-strings.cc
+++ b/test/cctest/test-strings.cc
@@ -476,7 +476,7 @@
     CHECK_EQ(results[i]->IsUndefined(), result->IsUndefined());
     CHECK_EQ(results[i]->IsNumber(), result->IsNumber());
     if (result->IsNumber()) {
-      CHECK_EQ(Smi::cast(results[i]->ToSmi())->value(),
+      CHECK_EQ(Smi::cast(results[i]->ToSmi()->ToObjectChecked())->value(),
                result->ToInt32()->Value());
     }
   }
diff --git a/test/cctest/test-strtod.cc b/test/cctest/test-strtod.cc
index ae1c00d..56b26ea 100644
--- a/test/cctest/test-strtod.cc
+++ b/test/cctest/test-strtod.cc
@@ -198,10 +198,58 @@
   CHECK_EQ(1234e304, StrtodChar("0000000123400000", 299));
   CHECK_EQ(V8_INFINITY, StrtodChar("00000000180000000", 300));
   CHECK_EQ(17e307, StrtodChar("00000000170000000", 300));
+  CHECK_EQ(1.7976931348623157E+308, StrtodChar("17976931348623157", 292));
+  CHECK_EQ(1.7976931348623158E+308, StrtodChar("17976931348623158", 292));
+  CHECK_EQ(V8_INFINITY, StrtodChar("17976931348623159", 292));
 
   // The following number is the result of 89255.0/1e-22. Both floating-point
   // numbers can be accurately represented with doubles. However on Linux,x86
   // the floating-point stack is set to 80bits and the double-rounding
   // introduces an error.
   CHECK_EQ(89255e-22, StrtodChar("89255", -22));
+  CHECK_EQ(104110013277974872254e-225,
+           StrtodChar("104110013277974872254", -225));
+
+  CHECK_EQ(123456789e108, StrtodChar("123456789", 108));
+  CHECK_EQ(123456789e109, StrtodChar("123456789", 109));
+  CHECK_EQ(123456789e110, StrtodChar("123456789", 110));
+  CHECK_EQ(123456789e111, StrtodChar("123456789", 111));
+  CHECK_EQ(123456789e112, StrtodChar("123456789", 112));
+  CHECK_EQ(123456789e113, StrtodChar("123456789", 113));
+  CHECK_EQ(123456789e114, StrtodChar("123456789", 114));
+  CHECK_EQ(123456789e115, StrtodChar("123456789", 115));
+
+  CHECK_EQ(1234567890123456789012345e108,
+           StrtodChar("1234567890123456789012345", 108));
+  CHECK_EQ(1234567890123456789012345e109,
+           StrtodChar("1234567890123456789012345", 109));
+  CHECK_EQ(1234567890123456789012345e110,
+           StrtodChar("1234567890123456789012345", 110));
+  CHECK_EQ(1234567890123456789012345e111,
+           StrtodChar("1234567890123456789012345", 111));
+  CHECK_EQ(1234567890123456789012345e112,
+           StrtodChar("1234567890123456789012345", 112));
+  CHECK_EQ(1234567890123456789012345e113,
+           StrtodChar("1234567890123456789012345", 113));
+  CHECK_EQ(1234567890123456789012345e114,
+           StrtodChar("1234567890123456789012345", 114));
+  CHECK_EQ(1234567890123456789012345e115,
+           StrtodChar("1234567890123456789012345", 115));
+
+  CHECK_EQ(1234567890123456789052345e108,
+           StrtodChar("1234567890123456789052345", 108));
+  CHECK_EQ(1234567890123456789052345e109,
+           StrtodChar("1234567890123456789052345", 109));
+  CHECK_EQ(1234567890123456789052345e110,
+           StrtodChar("1234567890123456789052345", 110));
+  CHECK_EQ(1234567890123456789052345e111,
+           StrtodChar("1234567890123456789052345", 111));
+  CHECK_EQ(1234567890123456789052345e112,
+           StrtodChar("1234567890123456789052345", 112));
+  CHECK_EQ(1234567890123456789052345e113,
+           StrtodChar("1234567890123456789052345", 113));
+  CHECK_EQ(1234567890123456789052345e114,
+           StrtodChar("1234567890123456789052345", 114));
+  CHECK_EQ(1234567890123456789052345e115,
+           StrtodChar("1234567890123456789052345", 115));
 }