Introduce MaybeHandle to police exception checking in handlified code.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 67810ef1524303f463c9b3b3775d11796a3f62c7..3b8e6f0da6faa05653f5de1052bbed47ba588b2a 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -3238,8 +3238,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ObjectFreeze) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
-  Handle<Object> result = JSObject::Freeze(object);
-  RETURN_IF_EMPTY_HANDLE(isolate, result);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, JSObject::Freeze(object));
   return *result;
 }
 
@@ -12318,16 +12318,17 @@ static const int kScopeDetailsObjectIndex = 1;
 static const int kScopeDetailsSize = 2;
 
 
-static Handle<JSObject> MaterializeScopeDetails(Isolate* isolate,
-    ScopeIterator* it) {
+static MaybeHandle<JSObject> MaterializeScopeDetails(Isolate* isolate,
+                                                     ScopeIterator* it) {
   // Calculate the size of the result.
   int details_size = kScopeDetailsSize;
   Handle<FixedArray> details = isolate->factory()->NewFixedArray(details_size);
 
   // Fill in scope details.
   details->set(kScopeDetailsTypeIndex, Smi::FromInt(it->Type()));
-  Handle<JSObject> scope_object = it->ScopeObject();
-  RETURN_IF_EMPTY_HANDLE_VALUE(isolate, scope_object, Handle<JSObject>());
+  Handle<JSObject> scope_object;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, scope_object, it->ScopeObject(), JSObject);
   details->set(kScopeDetailsObjectIndex, *scope_object);
 
   return isolate->factory()->NewJSArrayWithElements(details);
@@ -12371,8 +12372,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScopeDetails) {
   if (it.Done()) {
     return isolate->heap()->undefined_value();
   }
-  Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
-  RETURN_IF_EMPTY_HANDLE(isolate, details);
+  Handle<JSObject> details;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, details, MaterializeScopeDetails(isolate, &it));
   return *details;
 }
 
@@ -12413,8 +12415,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetAllScopesDetails) {
   List<Handle<JSObject> > result(4);
   ScopeIterator it(isolate, frame, inlined_jsframe_index, ignore_nested_scopes);
   for (; !it.Done(); it.Next()) {
-    Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
-    RETURN_IF_EMPTY_HANDLE(isolate, details);
+    Handle<JSObject> details;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, details, MaterializeScopeDetails(isolate, &it));
     result.Add(details);
   }
 
@@ -12461,8 +12464,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetFunctionScopeDetails) {
     return isolate->heap()->undefined_value();
   }
 
-  Handle<JSObject> details = MaterializeScopeDetails(isolate, &it);
-  RETURN_IF_EMPTY_HANDLE(isolate, details);
+  Handle<JSObject> details;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, details, MaterializeScopeDetails(isolate, &it));
   return *details;
 }