extensions: Use V8 Maybe APIs in NativeHandler

extensions/renderer/module_system.cc

Index: extensions/renderer/module_system.cc
diff --git a/extensions/renderer/module_system.cc b/extensions/renderer/module_system.cc
index 64e3502b41ef511de53c49d1d9a2e12e7ef13c52..8528cd7dfa94cc430c29079f5e23038fbe0e7ed5 100644
--- a/extensions/renderer/module_system.cc
+++ b/extensions/renderer/module_system.cc
@@ -195,12 +195,17 @@ void ModuleSystem::HandleException(const v8::TryCatch& try_catch) {
   exception_handler_->HandleUncaughtException(try_catch);
 }
 
-v8::Local<v8::Value> ModuleSystem::Require(const std::string& module_name) {
-  if (module_name.size() >= v8::String::kMaxLength)
-    return v8::Undefined(GetIsolate());
+v8::MaybeLocal<v8::Object> ModuleSystem::Require(
+    const std::string& module_name) {
+  v8::Local<v8::String> v8_module_name;
+  if (!ToV8String(GetIsolate(), module_name, &v8_module_name))
+    return v8::MaybeLocal<v8::Object>();
   v8::EscapableHandleScope handle_scope(GetIsolate());
-  return handle_scope.Escape(RequireForJsInner(
-      ToV8StringUnsafe(GetIsolate(), module_name.c_str())));
+  v8::Local<v8::Value> value = RequireForJsInner(
+      v8_module_name);

[not at google - send to devlin, 2015/06/24 16:43:03]

This should fit on 1 line; run "git cl format" before submitting.

+  if (value.IsEmpty() || !value->IsObject())
+    return v8::MaybeLocal<v8::Object>();
+  return handle_scope.Escape(value.As<v8::Object>());
 }
 
 void ModuleSystem::RequireForJs(
@@ -394,15 +399,11 @@ void ModuleSystem::LazyFieldGetterInner(
   NativesEnabledScope natives_enabled_scope(module_system);
 
   v8::TryCatch try_catch(info.GetIsolate());
-  v8::Local<v8::Value> module_value = (module_system->*require_function)(name);
-  if (try_catch.HasCaught()) {
+  v8::Local<v8::Value> module_value;
+  if (!(module_system->*require_function)(name).ToLocal(&module_value)) {
     module_system->HandleException(try_catch);
     return;
   }
-  if (module_value.IsEmpty() || !module_value->IsObject()) {
-    // require_function will have already logged this, we don't need to.
-    return;
-  }
 
   v8::Local<v8::Object> module = v8::Local<v8::Object>::Cast(module_value);
   v8::Local<v8::Value> field_value;
@@ -535,33 +536,39 @@ void ModuleSystem::RequireNative(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(1, args.Length());
   std::string native_name = *v8::String::Utf8Value(args[0]);
-  args.GetReturnValue().Set(RequireNativeFromString(native_name));
+  v8::Local<v8::Object> object;
+  if (RequireNativeFromString(native_name).ToLocal(&object))
+    args.GetReturnValue().Set(object);
 }
 
-v8::Local<v8::Value> ModuleSystem::RequireNativeFromString(
+v8::MaybeLocal<v8::Object> ModuleSystem::RequireNativeFromString(
     const std::string& native_name) {
   if (natives_enabled_ == 0) {
     // HACK: if in test throw exception so that we can test the natives-disabled
     // logic; however, under normal circumstances, this is programmer error so
     // we could crash.
     if (exception_handler_) {
-      return GetIsolate()->ThrowException(
+      GetIsolate()->ThrowException(
           ToV8StringUnsafe(GetIsolate(), "Natives disabled"));
+      return v8::MaybeLocal<v8::Object>();
     }
     Fatal(context_, "Natives disabled for requireNative(" + native_name + ")");
-    return v8::Undefined(GetIsolate());
+    return v8::MaybeLocal<v8::Object>();
   }
 
   if (overridden_native_handlers_.count(native_name) > 0u) {
-    return RequireForJsInner(
+    v8::Local<v8::Value> value = RequireForJsInner(
         ToV8StringUnsafe(GetIsolate(), native_name.c_str()));
+    if (value.IsEmpty() || !value->IsObject())
+      return v8::MaybeLocal<v8::Object>();

[not at google - send to devlin, 2015/06/24 16:43:03]

This should probably be a DCHECK since the code is only hit during testing. No
need to fail gracefully.

+    return value.As<v8::Object>();
   }
 
   NativeHandlerMap::iterator i = native_handler_map_.find(native_name);
   if (i == native_handler_map_.end()) {
     Fatal(context_,
           "Couldn't find native for requireNative(" + native_name + ")");
-    return v8::Undefined(GetIsolate());
+    return v8::MaybeLocal<v8::Object>();
   }
   return i->second->NewInstance();
 }